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THE 



PATHOLOGY OF THE TEETH 



WITH SPECIAL REFERENCE TO THEIR 



ANATOMY AND PHYSIOLOGY. 



CARL WEDL, M.D., 

PROFESSOR OF HISTOLOGY IN THE UNIVERSITY OF VIENNA, ETC. 



TBANSLATED FR03I THE GEBMAN 

BY 

W. E. BOARDMAN, M.D. 

With Notes 

by 

T. B. HITCHCOCK. M.D., D.M.D., 

professor of dental pathology and therapeutics in harvard university, etc. 

With One Hundred and Five Illustrations. 



PHILADELPHIA: 

LINDSAY & BLAKISTOK 

1872. 




nT 



d\ 






Entered according to Act of Congress, in the year 1872, 

By LINDSAY A BLAKISTOX, 

In the Office of the Librarian of Congress, at Washington, D.C. 



SHERMAN cC- CO.. PR IX TEES. 



TEANSLATOE'S PEEFACE. 



Prof. "Wedl is widely known as a very expert and thorough inves- 
tigator and a distinguished scholar. His "Rudiments of Pathological 
Histology," published by the Sydenham Society in 1855, will justify 
the assumption that anything from his pen will prove valuable. 

A definite idea of the object and scope of the present work may be 
obtained from the author's preface and table of contents. Prom these 
it will be seen that the work covers the whole ground of the Anatomy, 
Physiology, and Pathology of the teeth and their adnexa. As far as 
was practicable, the researches of others were made use of, and, in ad- 
dition, there will be found much that is entirely original. Indeed, the 
work forms the most complete treatise of its kind that has appeared in 
any language. \Vhen we consider the vast amount of labor required 
in the original investigations of the author, in the collection of material 
and the reviewal of the very extensive and exceedingly scattered litera- 
ture of the subjects of which he treats, it must be acknowledged that 
he is deserving of great credit. It is believed that the work will prove 
a valuable one for the dental profession in this country, since the recent 
advances which have been made here in the requirements of the students 
of dental science necessitate a complete work for the purpose of a guide 
in future original investigations as well as of studying the results of 
the researches which have already been made. General practitioners, 
also, of medicine and surgery, and students of histology will find in it 
much of interest and value. 

I have endeavored to make the translation as literal as possible and, 
at the same time, to avoid German idioms ; this has been a difficult 
task on account of the peculiarities in the author's style of writing as 
well as of the difficult nature of the subjects of which he treats. I have 



VI TRANSLATOR S PREFACE. 

been unable to obtain, for the purpose of comparison, several works 
and journals to which he refers and from which he quotes. I have 
thought it best to retain everything and to add but little. It was sug- 
gested that explanatory notes should be introduced in reference to 
many points with which students of dental science alone might be un- 
acquainted, but it was found that too much space would be required in 
order to make these complete. Many of the works to which refer 
is made in the text are readily accessible, and from them the reader 
can obtain more satisfactory information and at greater length, than 
could be included within the limits of ordinary n 

I am well aware that the critical reader will find many blemish 
the translation and inelegant diction, which I trust will be pardoned. 
Perhaps I have not correctly appreciated the author's meaning in - 
instances; errors of this description I hope the critic will clearly pr 

Prof. Hitchcock has carefully reviewed the translation, and the few- 
ness of the notes which he has found necessary t<< add will indicate 
clearness and completeness of the author*.- treatment of 
I am greatly indebted t<> Prof. Bitchcock for the - which I 

have derived from conversations with him and from his library and 
pathological collection. 

Before the appearance of the present work, Prof. Wed! published an 
•• Atlas to the Pathology of the Teeth.'* which contains one hundred 
and forty-five beautiful engravings in illustration of malformations and 
diseases of the teeth, together with explanations of the - h in 

German and English. Although this Atlas i> not absolutely essential 
to the understanding of the present work, still, as 1 have found, 
full appreciation of the latter will be facilitated by the 
former, especially of those p trtions to which reference is made in 
text. 

The illustrations, with which the book is enriched, are fron 
types, the same as used in the original German edition. The autl 
index has been enlarged considerably : though still incomplete, it will. 
I believe, commend itself to the readers as a valuable addition. 

Prof. AVedl, reserving the right of translation, sent a copy of the 
original edition to his friend and former pupil. Dr. Francis II. Brown 
of this city, with the request that he would translate and publish the 
same. He concluded, however, that his numerous duties would em 
sitate too great a delay, and so he honored me with the requ 



TRANSLATOR S PREFACE. VII 

sume the duty. I must here express my sincere .thanks to him for his 
undiminished interest in the progress and success of the work, and for 
much valuable assistance. To many others, also, whom it is my 
privilege to consider my friends, I take this opportunity of renewing 
my thanks for their uniform kindness, their willing and valuable aid 
in many ways. 

In closing, I will express the hope that the present work will con- 
tribute to the advancement of the study of dental science in this country, 
and that its readers will derive at least as much information and pleasure 
from its perusal as I have received in the more laborious work of its 
translation. 

W. E. BOARDMAN, M.D. 

Bostox, Mass., September, 1872. 



AUTHOR'S PREFACE. 



The collection of the vast amount of material requisite for a work 
upon a special branch of pathology is attended with manifold difficulties. 
Our efforts are the sport of capricious fortune and must be continued 
unremittingly during many years before a foundation can be laid. 
Carabelli made collections during about twenty, and Heider during 
twenty-three years, and they succeeded in obtaining valuable series of 
specimens illustrating the anomalies of teeth. The latter collection, 
however, was by far too limited for the requirements of a special study ; 
indeed, this furnished only thirty-four illustrations for the "Atlas to 
the Pathology of the Teeth," not one-fourth of the entire number. 
Heider and I, therefore, were compelled to devise some method for 
obtaining, in the first place, the necessary material for our work. At 
our request, we were very kindly furnished with thousands of extracted. 
teeth from the Hospital of the Charity Friars in Vienna. The teetli 
alone, however, are insufficient for our purpose, as is self-evident ; it is 
necessary to observe them in situ, in the cadaver and the skeleton, in 
order to study the connection of the phenomena in succession. In com- 
mon with those of experience : I can recommend such a collection of 
diseased teeth as a fertile source of instruction to the practical dentist. 

By the kindness of my esteemed friend, Dr. Ph. Steinberger, Vice- 
President of the Austrian Dental Society, I have had the opportunity. 
not only of examining Ileider's collection together with the children's 
skulls which were collected by the dentist Terzer, and of making use 
of a number of plaster casts, but I have also had at my disposal the 
dental library and journals. I am indebted to numerous colleagues, 
whose names are introduced in connection with the proper illustrations. 
for very important additions to the materials at my disposal. 



X AUTHOR S PREFACE. 

After the death of Heider, his wife, Marie Heider, allowed me to 
peruse his manuscripts upon subjects connected with dentistry. These 
comprised outlines of lectures upon dentistry, which I availed myself 
of, a minute description of the exterior of the teeth, which I have fol- 
lowed, almost word for word, and a synopsis of abnormal sets and 
anomalies of teeth, which I have rearranged under different heads with 
additions, illustrations and special explanations. Finally, before his 
death, Heider furnished me with written communications concerning 
his clinical observations with reference to caries and inflammation of 
the root-membrane, which I have introduced under his name. 

The papers published by Heider and myself in common and, likewise, 
by myself alone, in the "Deutsche Yierteljahresschrift fur Zahnheil- 
kunde," I have introduced in the text either unchanged or with addi- 
tions, or rewritten. 

Special reference has been made to the ancient and modern literature, 
so far as space and the means at my disposal would allow, and in this 
connection I have derived much assistance from the analects of A. zur 
Nedden, in the "Deutsche Viertelj. f. Zahnh." Unfortunately, I was 
unable to avail myself of several valuable monographs which were not 
to be obtained through the booksellers. 

After much reflection upon the subject, I decided to divide the 
morbid processes into seven groups or families, and to consider the dis- 
eases of the different organs in connection with each group. In this 
way, I think, the subjects have been treated in a more connected man- 
ner. The anatomico-physiological basis has been adhered to strictly 
throughout the book and, when it has appeared advantageous, com- 
parative pathologico-anatomical data have been introduced in order to 
elucidate the processes. Whenever the needs of the dentist seemed to 
require it, clinical observations have been combined with the patho- 
logico-anatomical and, in this way, more life has been infused into 
the latter. 

In such a recent doctrine as the pathology of the teeth, it is absolutely 
necessary to dwell upon isolated observations which cannot be con- 
firmed until a later period. 

The pathological is preceded by an anatomico-physiological part 
which, I think, contains several new points, the results of my own 
observations. 

For the more minute literature of this portion of the subject, of 



AUTHOR S PREFACE. XI 

which, perhaps, there is an excess at present, I refer to the familiar 
text-books. In this part, also, it was my endeavor invariably to keep 
in view the requirements of the dentist, and, with this idea, therefore, 
I have also paid especial attention to the growth of the jaws which is 
connected so intimately with the anomalies in the position of the teeth. 

1 have endeavored to give a definite idea of the connection between 
the various anomalies of formation, which are so important to the den- 
tist, and an exposition of the phenomena of development. Many gaps 
in our knowledge of the latter processes are yet to be filled up, a fact 
which is only too apparent ; but it may safely be said that many of the 
pathological processes, which occur in the later years of life, owe their 
origin to an abnormal process in the development of the teeth. 

The inflammations which came within the province of the present 
work have been considered connected^ ; the atrophies, particularly the 
changes incident to old age, have received especial study. I have 
taken into consideration those new-formations which have their seat in 
the jaws and stand in a certain relation to the teeth, in addition to 
those which belong properly to the teeth. An interstitial growth of 
bone and dentine has been demonstrated, especially in connection with 
the new-formations in the teeth, but with reference to other new-for- 
mations also. I may have exposed myself to criticism by classing 
caries of the teeth with anomalies of the secretions. I think, however, 
my exposition of the subject will justify my course. I have endeavored, 
as far as our present knowledge will allow, to place the neuroses upon 
a scientific basis. 

Although the book forms a complete work by itself, I have, never- 
theless, continually made reference to the "Atlas to the Pathology of 
the Teeth," without, however, encroaching upon the text. The Atlas 
and the Pathology herewith presented, together form a complete whole, 
and the understanding of the latter will be promoted essentially by the 
former. All the illustrations in the present work are original and were 
drawn upon wood by Dr. Heitzmann, of Vienna, with the rare skill 
peculiar to him, and were engraved with great accuracy by Mr. Flegel, 
of Leipsic. I am persuaded that they will render valuable aid in the 
appreciation of the text. The explanation of each figure is given in 
detail and thereby interruptions in the text are avoided. 

In closing, I hope that this book, which, I may truly say, has re- 
quired a considerable expense of time and labor, may meet with such a 



XU AUTHOR'S PREFACE. 

favorable reception as was accorded to the Atlas, and that it may aid 
in directing more attention to the doctrine which hitherto has been 
neglected somewhat as a whole, although portions of it. to be sure, 
have been elaborated. 

Carl AVedl. 
Vienna. November 4ih. 1870. 



CONTENTS. 



Translator's Preface, 
Author's Preface, 
Introduction, 



page 

5 

9 

17 



PART I. 



ANATOMY AND PHYSIOLOGY. 



General Characters of the Teeth, .... 








28 


Classification of the Teeth, 








30 


Description of the Temporary and Permanent Teeth, 








31 


Temporary Teeth, 








38 


The Hard Tissues of the Teeth, .... 








43 


Cement, ......... 








51 


The Pulp, 








54 


The Gum, 








57 


The Root-Membrune, Periosteum of the lioot, 








58 


Development of the Teeth, ..... 








60 


First Dentition, 








73 


Second Dentition, ....... 








76 


Third Dentition, . . 








87 


Growth of the Jaws, 








88 


PART II. 


PATHOLOGY. 











Irregularities in the Formation of Teeth, 

1. Irregularities of Size, .... 

2. Irregularities of Number, .... 

Deficiency of Teeth, .... 



98 

98 

99 

104 



XIV 



CONTENTS. 



Irregularities of Arrangement, 

A. Irregularities in the Arrangement of the entire Dental 

Arches, .......... 

B. Irregularities in the Position of the separate Permanent 

Teeth, 

Central Incisors, 

Lateral Incisors, 

Canine Teeth, . . ... 

Bicuspids and Molars, 

Irregularities in the Position of the Milk Teeth, 

C. Irregularities in the Position of separate Permanent Teeth 

which are Imbedded within the Jaw, 

D. Retention of Teeth without Displacement, 
Irregularities of Structure, .... 

a. Flexions and Torsions of the Crowns and Roots 

b. Excessive Growth upon the Crowns and Roots, 

c. Defective formation of the Crowns and Roots, 

d. Blending or Fusion and Coalition or Concrescence of adja 

cent Teeth, .... 

e. Malformations, .... 



PAGE 

108 
108 



II. Inflammations, 

Pulp, 

Gum, 

Diseases occasioned by the First Dentition, 
Diseases occasioned by the Second Dentition, 
Root-Membrane, ...... 

Alveolar Abscess, ..... 

Nasal Cavity and Antrum, .... 

III. Atrophies, 

Pulp, 

Senile Dentine, ...... 

Cement, ....... 

Resorption of Senile Dentine and Cement, 
Enamel, ....... 

Surfaces produced upon the Crowns by Attrition. 

Gum, 

Root-Membrane and Alveolus, . 

Maxillary Periosteum and Maxillary Bones, 



IV. Hypertrophies, 
Cement, 

Root-Membrane, 
Gum, . 



CONTENTS. 



XV 



V New-Formations, 



VI. 



Pulp, . . • 

New-Formations of the Hard Dental Tissues, 
Musket-balls in the Teeth of Elephants, 
New-Formations of Osseous Substance in connection 

scesses in the Ivory of the Tusks of Elephants, 
Fractured Teeth, . 
Cement, Osteomata, Exostoses, 
Eoot-Membrane, . 

Gum, 

Mucous Membrane of the Mouth 
Alveolar Processes, 
Cysts of the Jaws, 
Osteophytes upon the Jaws, . 
Enostoses in the Jaws, . 
Chondromata of the Jaws, . 
Fibromata of the Jaws, 
Sarcomata of the Jaws, 
Gelatinous Tumors, Myxomata, 
Carcinomata, 
Antrum, .... 



Anomalies of the Secretions, 

Saliva, 

Coating upon the Teeth, 

Tartar, Odontolithus, . 

Caries of the Teeth, . 

Appearances presented by the Enamel in Caries, 

Appearances presented by the Dentine in Caries, 

Appearances presented by the Cement in Caries, 

Extension of Caries to the Koots, 

Caries of the different kinds of Teeth, m . 

Frequency of Caries, 

Effects of Carious Teeth upon the rest of the Body 
Caries of Keinserted Human Teeth, . 
Caries of Teeth made of Ivory from the Hippopotamus, 
Experiments upon the Teeth with Various Substances, 
Caries of the Teeth of Animals, .... 

Theories of Caries, ....... 



with Ab- 



VII. Neuroses, 



Alphabetical Index, 



PAGE 

284 
285 
286 
301 

304 
307 
312 
316 
319 
321 
322 
331 
335 
337 
339 
340 
343 
348 
349 
351 

354 
354 
357 
361 
367 
376 
384 
391 
392 
393 
397 
403 
404 
406 
407 
410 
411 

426 

445 



INTRODUCTION. 



If it be asked, with reference to the history of dental science, 
why the doctrines of the latter have matured at a comparatively 
late period, the answer is obvious, namely, because its study 
was not pursued systematically as that of a natural science. 
Until about the middle of the last century, dentistry was almost 
exclusively in the hands of the laity, not of physicians, and was, 
and is at the present time, neglected by the latter as a sort of 
stepchild of surgery. The so-called dentists of former times 
had no knowledge of the discoveries of the great anatomists of 
the fifteenth and sixteenth centuries ; indeed, it was not pos- 
sible for them, since they did not have access to any scientific 
models, and consequently knew nothing about them. They took 
no pains to determine the simplest matters of fact ; disputed as 
to the number of teeth possessed by men and women, respec- 
tively. The belief was prevalent for a long time that the milk 
teeth have no roots. The renowned French dentist, P. Fau- 
chard (1728), (Carabelli, Geschichte der Zahnheilkunde and 
Linderer's Zahnheilkunde), and later, Bourdet (1757), endeav- 
ored, upon anatomical grounds, to disabuse men of this errone- 
ous idea ; nevertheless, forty years afterwards, I am sorry to 
say, we read in German writings that the milk teeth have no 
roots, but are capable of giving off roots, if they are not detached 
at the proper time. The great J. Hunter, Fox and his pupils, 
were the first to follow a system of natural science and to 
initiate unprejudiced and trustworthy methods of observation, 
while Germany, during the preceding and in the first decade of 
the present century, took scarcely any share in the progress of 
dental science. 

If we call to mind the history of the forceps, we now wonder, 

2 



18 INTRODUCTION. 

and with reason, that people ever ventured to extract teeth 
without having informed themselves beforehand with regard to 

Or o 

the construction and arrangement of the crowns and roots in 
the jaw, &e. Indeed it is the fact, that they ventured only with 
great reluctance to extract a tooth for more than a thousand 
years after Celsus. Notwithstanding the manifold improve- 
ments, during the preceding and commencement of this century, 
in the art of extracting teeth, it was not until our own time, 
principally through the exertions of J. Tomes, Richardson and 
others, that the mechanism of the forceps was accurately 
adapted to the separate teeth, in the upper and lower jaw, on 
the right and left side, and to their arrangement in the jaw. 
so that now there is danger of fracturing the tooth, its socket, 
or the jaw, in exceptional cases only. 

It is conceivable that, in consequence of the danger attend- 
ing the extraction of teeth, a great variety of expedients were 
employed for the benefit of the unfortunate patients, and that 
attempts were made to ascertain the causes of the pain. In the 
absence of all anatomical and physiological knowledge, the 
gnawing and piercing pains seem to have given rise to the idea 
of the presence of parasites. The fringes of the thickened peri- 
osteum of the root, or the root pulps, which remain attached to 
teeth after their extraction, may have given weight to the hy- 
pothesis that worms are developed within the tooth and give rise 
to the pain. Indeed, it was said, worms might originate at any 
part per generationem cequivocam. This hypothesis held po- 
sion of men's minds during the seventeenth century, and still 
prevails among the common people whose character for implicit 
belief in traditions is by no means eradicated. The belief in the 
existence of the worms was so general that, in 1757, J. Ch. 
Schaffer, of Regensburg, published a monograph, entitled " The 
Imaginary "Worms of the Teeth," wherein he proved that the 
existence of these worms is a chimera, and that the so-called 
tooth-worms, which fall from the teeth after fumigation with 
winter-cherry and wax. are nothing but the volatilized germs of 
the winter-cherry seed-corns. Thus dentistry prolonged a 
wretched existence, depending for its support upon popular 
tradition. 



INTRODUCTION. 19 

The instructors in the old universities trod, for the most part, 
in a beaten track of doctrine which was based upon faith in au- 
thority, but when, in the study of the natural sciences in gen- 
eral, inquiries were instituted with reference to the connection 
of cause and effect between separate phenomena, and the latter 
were subjected to the most searching analysis and referred to 
fundamental laws of general application, then the natural 
sciences made such comparatively rapid strides that they soon 
invaded every branch of human knowledge. As the mass of 
material to be digested accumulated, the necessity of a further 
and further division of labor in the field of natural sciences be- 
came apparent, and from this principle of division has resulted, 
among others, the branch of dental science ; this was elevated to 
the rank of a special study, and demanded, therefore, special in- 
struction, which, in England and the United States of America 
particularly, has attained a high degree of excellence. During 
the last ten years, thanks to the exertions of individuals, den- 
tistry has entered upon a scientific career in Germany, and 
there is reason to expect that it will soon be rescued from the 
realms of mere empiricism. 

While we recognize fully the endeavors of those of former 
times to aid their suffering fellow-beings with the means at their 
command, it must, however, be conceded that it was not until 
modern times that the reach of thought was broad enough to 
enable men to establish a truly scientific basis for a rational 
system of therapeutics. Anatomy and physiology, the guiding 
stars of pathology, have by degrees shed their salutary light 
upon dentistry, and afforded an insight into the life of the tooth, 
though, to be sure, it is only partially satisfactory. Bearing 
this in mind, I have deemed it advisable to preface the Pa- 
thology with a section upon Anatomy and Physiology. 



THE 



PATHOLOGY OF THE TEETH, 



PAET I. 
ANATOMY AND PHYSIOLOGY. 

The dentist is occupied specially with the cavity of the mouth, 
a thorough knowledge of which is indispensable to him, and by 
the consideration of which, from his standpoint, much is eluci- 
dated which the anatomist cannot touch upon without interfer- 
ing with his more general plan. It does not come within the 
scope of the present work to enter into full anatomical descrip- 
tions, but the object in view necessitates rather references to 
details which receive only slight, if any, notice from the anato- 
mist, but which acquire importance in dentistry. 

With regard to the physiological portion of our subject, which 
is connected so intimately with the anatomical portion that the 
two cannot conveniently be considered apart, our knowledge 
has not made very marked progress since, in the investigations 
into the individual life of the tooth, many difficulties are to be 
contended with, and extensive, subtile researches are requisite. 
Many of the latter have already been made, but, at present, 
their results are widely scattered and do not yet admit of in- 
corporation into a profitable whole. The advances made in our 
knowledge of the laws of embryonic development have indeed 
cleared up many obscure points, yet the theory of the complex 
animal-cell-life still rests upon widely diverging hypotheses and 
mostly arbitrary interpretations. 

The bony framework of the cavity of the mouth is formed, 



22 ANATOMY AND PHYSIOLOGY. 

laterally, by the alveolar portions of both jaws, and, above, by 
the palatal plates of the upper jaw and palate bone. 

- The alveolar process of the superior maxillary bone forms a 
projection from the inferior portion of the body of the jaw, in 
the form of a comb, and, upon the inside, is in relation with the 
palatal plates of the upper jaw and palate bone. It incloses a 
row of cells which are arranged in the form of an elliptic arch 
and serve for the reception of the roots of the teeth. 

Each tooth-cell [alveolus) is composed of a finely porous, com- 
pact plate of bone which, when it is perfectly formed, is sunk 
into the spongy tissue of the jaw, in the form of a cul-de-sac or 
funnel, and, towards the open extremity, comes into intimate 
relation with the cortical substance of the bone. At the closed 
extremity of the cell, there are a few quite large foramina 
which lead to the alveolar canals, and serve for the passage of 
the dental nerves and vessels. These relations may be demon- 
strated most clearly in the jaws of children by the careful re- 
moval of the facial wall, together with the spongy tissue, so that 
the cells and their delicate attachments to the cortical substance 
of the bone at their open extremities are exposed to view. The 
cells then are presented in the form of clearly defined, conical 

prolongations of compact bony tis- 
sue (Fig. 1). Again, if longitud- 
inal sections be made through the 
teeth and jaw of an adult before 



Fig. 1.* 




he has attained to old age, it will 
be seen that the root lies within a 
quite firm bony capsule with thin 
walls, which dips down from the 

alveolar border, and is surrounded by a very lax, spongy, bony 

tissue. 

* Fig. 1 shows the alveoli of milk teeth of the right segment of the upper 
jaw, from which the investing spongy bony tissue has been removed, and also 
the rounded alveolus (a) of the first permanent molar. The facial wall of 
the alveoli does not extend so far downward as the lingual wall, and presents 
an excavated, crescentic margin; the third or lingual roots of the two milk 
molars do not appear in the section. The posterior external root of the second 
milk molar rests upon the convex surface of the alveolus which incloses the 
crown of the first permanent molar. Natural size. 



SUPERIOR MAXILLARY BONE. 23 

The number of sockets corresponds with that of the roots of 
the teeth. Teeth with one root have a single socket, while those 
with more than one root have sockets composed of two or three 
cells, according to the number of roots. As the cells are casts, 
as it were, of the roots, they correspond with the latter in form 
and direction, and the ridge-like elevations of the cells fit into 
the furrows in the roots. 

The alveoli are separated from each other by bony septa, 
which increase in thickness towards the apices of the former, 
and upon the alveolar border present a few foramina, which are 
most conspicuous in the jaws of young persons, for the passage 
of the interalveolar vessels and nerves. The cells of the com- 
pound alveoli, moreover, are separated from each other by ad- 
ditional septa for each root. Hence, in the cells for the upper 
teeth with three roots we find, in addition to the anterior and 
posterior primary septa, two secondary septa, one of which has 
an antero-posterior direction and the other extends from the 
outside towards the inside. The anterior or facial festooned 
border at the free extremities of the sockets is excavated more 
deeply than the posterior or lingual border. 

The border of the alveolar arch of the upper jaw from a 
young adult, when viewed from the facial side, presents a double 
curve, namely, one with a downward inclination, from behind for- 
wards, with the convexity directed downwards, and one extend- 
ing upwards towards the anterior segment of the arch, and with 
its concavity directed downwards. Upon the lower jaw the re- 
lations of the serpentine curve are the reverse of the preceding, 
i. e., the convexity of the upper corresponds to the concavity of 
the lower arch. This undulatory curve is scarcely perceptible 
on the alveolar arches of old people or young children. 

The external or facial wall of the alveolar portion of the 
upper jaw is thinner and more yielding than the internal or 
lingual wall, and from the former project oblong folds which are 
produced by the subjacent roots of the teeth. These may be 
felt distinctly even during life, and afford some evidence with 
regard to the size and direction of the roots. They are the so- 
called juga alveolaria. Not unfrequently a portion of the alve- 
olar wall is wanting, together with the corresponding portion of 



24 ANATOMY AND PHYSIOLOGY. 

the dental socket, and the root of the tooth is exposed in the 
obiong opening. 

'The body of the upper jaw incloses a cavity of great importance 
to the dentist on account of the diseases which have their seat 
within it. This is called the Maxillary Sinus or Antrum of 
Highnore; its floor is situated above the sockets of the molars 
and second bicuspid, and its roof is formed by the inferior por- 
tion of the wall of the orbit. The anterior and posterior walls 
are formed by the corresponding surfaces of the jaw. The in- 
ternal wall towards the nasal cavity presents an aperture which 
communicates with the middle meatus of the nose and is con- 
tracted considerably by the inferior turbinated bone and by por- 
tions of the ethmoid and palate bones. The floor of the antrum 
frequently presents conical processes, which are occasioned by 
the projection of the apices of the roots of the above-mentioned 
subjacent teeth, and also one or two more or less prominent lam- 
inae by which the bottom of the cavity is divided into compart- 
ments. The root of the second bicuspid tooth is situated be- 
neath the anterior smaller division of the cavity. The antrum 
belongs to the S} 7 stem of communicating cavities which are lined 
by the nasal mucous membrane, and, in common with which, it 
is frequently the seat of disease; it forms a portion of the 
respiratory apparatus. 

The inferior maxillary hone, the lower jau\ is curved in the 
form of a parabola, and consists of a body and two extremi; 
the latter ascend in vertical planes and are called the rami or 
branches. Both the body and the rami present for examination 
an external or facial and an internal or lingual surface, directed 
towards the cavity of the mouth. On the external surface of 
the body, equidistant from the median line on either side, is a 
roundish, occasionally transversely divided foramen which com- 
municates with the inferior dental canal, and is called the an- 
terior or external orifice of the latter {foramen mentale). It is 
situated six to ten millimetres below the alveolar border, usually 
in a perpendicular line drawn between the first and second bi- 
cuspids, and not infrequently a little more anteriorly or pos- 
teriori} 7 , beneath the first or second bicuspid. 

Extending obliquely upwards from the vicinity of the first 



INFERIOR MAXILLARY BONE. 25 

molar is a well-marked ridge, the external oblique line, which is 
continuous with the. anterior border of the ramus, and near the 
posterior segment of the alveolar process is bounded by a shallow 
groove. The corresponding portion of the external wall of the 
lower jaw is rendered thicker and less yielding by this promi- 
nent ridge, a condition of practical importance to the dentist. 

The internal surface presents, opposite the median line, a 
rough eminence, the internal mental process (prominentia men- 
talis int.). Upon either side of this process commences a ridge, 
the internal oblique line, which extends obliquely upwards towards 
the molar teeth, and serves to give strength to the alveolar pro- 
cess upon the lingual side of the jaw, and for the attachment of 
muscles. 

The inferior border of the lower jaw is rounded, and above it 
rises the alveolar process, which in adults contains sixteen al- 
veoli for the reception of the teeth. The last three alveoli on 
either side are compound, each being divided into two secondary 
cells by an additional septum. The alveolar process of the 
lower jaw describes a parabolic curve, and its posterior extremi- 
ties are separated by a wider interval than are those of the 
upper jaw. This inequality, which would not permit the mutual 
adaptation of the teeth, is compensated for by the fact that the 
superior alveolar process has an outward inclination throughout 
its whole extent, while the lateral portions of the inferior pro- 
cess are inclined inwards, and hence the teeth preserve a corres- 
ponding inclination. As has already been stated, the facial 
wall of the superior alveolar process is thinner and more elastic 
than the lingual, but this is true of the facial wall in the lower jaw 
only as far as the region of the first molar, beyond which point 
the lingual wall is thinner than the facial. The concavities of 
the festooned alveolar border of the lower jaw are directed up- 
wards, and the septa between the alveoli project beyond the 
level of the latter. 

The rami of the inferior maxillary arch, forming obtuse angles 
with the body, extend obliquely upwards and a little outwards, 
and each terminates in two processes separated by a crescentic 
notch ; the anterior or coronoid process rises behind the last 
alveolus, frequently encroaches upon the latter to. a consider- 



26 ANATOMY AND PHYSIOLOGY. 

able degree, so that its lingual surface even not infrequently 
renders the upper wisdom tooth difficult of access ; the posterior 
op condyloid process is of much greater importance ; it terminates 
in a small, cylindriform, convex, articular condyle, the long 
axis of which is transverse. The long axes of the two condyles 
are not horizontal, but are inclined somewhat obliquely upwards 
and backwards, so that if prolonged they would meet at an angle 
of about 150°. Articular condyles, however, are met with 
whose long axes are nearly horizontal. 

The lingual surface of the ascending ramus presents the pos- 
terior or internal orifice of the inferior dental canal, partially 
covered in front b} r a small bony plate, the spinous process of 
the lower jaw. The inferior dental canal commences at this 
opening, and, decreasing in size, extends through the body of 
the jaw beneath the alveoli, terminating at the mental foramen, 
and is lined by a thin lamella of bone, finely porous upon its 
inner surface. 

The articulation of the lower jaw, by means of which the ap- 
proximation of the two jaws is effected, has recently been made 
the subject of special investigation by C. Langer.* The ar- 
ticular or glenoid fossa of the temporal bone is formed partly 
by the squamous portion and partly by the vaginal process or 
tympanic lamina of the latter, and is smooth only upon its 
anterior portion. In front of the fossa is the eminentia articu- 
lar is, the whole of which is concerned in the formation of the 
joint, and usually is obliquely disposed. The interarticular 
cartilage (meniscus interarticularis) is a biconcave plate which 
is inserted between the articular eminence above and the con- 
dyle below, and is connected with both bones. The edges of its 
smooth surfaces are attached upon either side to the articular 
capsule, so that the joint is divided into two cavities. The only 
proper ligament of the joint is situated externally, the t 
mentum laterale, which is attached above to the root of the zy- 
goma and below to the neck of the lower jaw. 

The mobility of the lower jaw is limited. The movements of 
the two joints are simultaneous and take place in three direc- 

* Sitzungsbericbte der Wiener Akademie. I860, and Lehrbueh der menscb- 
liclien Anatomie, I860. 



MOVEMENTS OF THE LOWER JAW. 27 

tions, namely, forwards or backwards (sagittal), from side to 
side (horizontal), and downwards (frontal). In the latter, the 
articular condyle glides upon the articular eminence and the 
chin is moved downwards in the arc of a circle. 

The movements in mastication are accomplished by four pairs 
of powerful muscles, two of which are attached to the external, 
and two to the internal surface of each ramus of the lower jaw. 
They are the masseter, temporal, external, and internal ptery- 
goid muscles. C. Langer* investigated their actions, which he 
describes as follows : " The masseter, temporal, and internal 
pterygoid muscles elevate the jaw and press the lower dental 
arch against the upper. Their only antagonists are the hyoid 
muscles and the platysma. The external pterygoid exerts no 
action in a vertical direction, but draws the jaw and the men- 
iscus forwards in a horizontal plane and assists, therefore, in 
the forcible opening of the mouth ; hence, in the latter respect, 
it is an antagonist of the first mentioned muscles and cannot 
act in unison with them except in moving the jaw forward when 
it is closed. On the other hand, the three elevators are re- 
quired to move the jaw backwards, since their action has a ten- 
dency in a direction from in front backwards and in a horizontal 
plane. Symmetrical contractions give rise to the sagittal 
movements ; asymmetrical movements, to either side, require 
the contraction of the muscles upon one side alone, and, as it 
appears, the action of the external pterygoid is the principal 
element in the production of this movement." 

The three principal movements of the lower jaw admit of an 
endless variety of modifications in which the different kinds of 
teeth variously participate. As a general rule, the movements 
of the front teeth are more extensive than those of the back 
teeth. In the lateral movement, the teeth of one half of the 
lower jaw are displaced to the outside of the corresponding 
teeth of the upper jaw, while the teeth of the other segment are 
removed to an equal distance towards the median line. The 
extent of the lateral movements of the teeth bears a definite re- 
lation to the construction of the articulation of the lower jaw, 
and is diminished with the more horizontal position of the 

* Anatomie S. 238. 



28 ANATOMY AND PHYSIOLOGY. 

articular condyle. In the latter cases, approximation of the 
jaws is effected with the teeth more nearly in a perpendicular 
plane. The difference in the extent of the movements of the 
front and back teeth, respectively, is most noticeable in the 
frontal movement, while in the sagittal it is scarcely perceptible. 

The three different movements employed in mastication pass 
into each other, but these transitions are impossible while any 
one movement is exercised to its maximum degree. In biting, 
the frontal movement is employed; in cutting, the sagittal, and 
in triturating the food, all three movements occur in rapid 
succession. 

The entire mechanism of the act of mastication acquires a 
still more complicated character when the undulatory curves 
and the inclinations of both the upper and lower rows of teeth 
are taken into consideration. In consequence of these, the 
movements of the separate teeth are variously modified. The 
mechanism, also, is advantageous for the purpose of fixing the 
morsels which are to be triturated. 

General Characters of the Teeth. — All the teeth may 
be considered as wedges. These assume the most varied forms 
in the animal kingdom, and occur in the form of chisels, sharp- 
pointed or blunt, narrow or broad, long or short, rounded or 
laterally compressed cones and plates ; their forms are either 
simple or compound ; the long conical teeth, in some cases, serve 
as weapons of offence and defence. By the interlocking of the 
wedges of the lower jaw with those of the upper, and the pow- 
erful action of the muscles of mastication, solid articles of food 
are crushed. Portions which escape uncrushed are replaced 
again between the wedges by means of the action of the tongue 
and the muscles inserted into the sides of the mouth. By these 
means, assisted by the mucous and salivary secretions which are 
abundant during the process of mastication, the solid food is 
converted to a pulp suitable for deglutition. 

The specific gravity or density of the teeth varies considerably. 
At my request, Dr. B. Kopezky examined sections of fourteen 
teeth, four deciduous and ten permanent teeth, with reference 
to this point. In the former, the density varied from 1.09 to 
2.17 ; in the permanent teeth he found a variation between 1.98 



CLEAVAGE OF THE TEETH. 29 

and 2.53, amounting, therefore, to 0.55. The lowest sp. gr. was 
afforded by a much worn upper mola"r with horny translucent 
roots and containing a dentinal new-formation which completely 
filled the pulp-cavity ; the greatest density was found in a much 
worn bicuspid. The permanent teeth showed an average density 
of 2.25. These summary statements, based upon the examina- 
tion of a small number of teeth, cannot be regarded as conclu- 
sive, and are merely intended as an incentive to more extended 
investigations with reference to varieties in individuals and at 
different ages. 

The hardness of the dentine of human teeth is placed by 
Kopezky between 5 and 6 in Mok's scale,* i. e., between apatite 
and felspar ; the enamel, which emits a spark with steel, ranks 
with 7 in the order of hardness. 

The property of cleavage may be demonstrated in the crowns 
and roots of teeth by means of the vice, and in teeth which have 
been dried and treated for a considerable time with dilute hydro- 
chloric acid ; they split in certain directions which are deter- 
mined by the fact of their possessing single or multiple papillary 
elevations. Incisors, especially the hard and brittle ones of old 
people, are well adapted to show this property ; it is not an un- 
common occurrence for these to break into median and lateral 
halves, merely from compression exercised with slowly increased 
force upon the prominent portions of the facial and lingual sur- 
faces. A similar division of round, straight roots may be 
effected, but this is impossible with curved roots, as will be evi- 
dent, except in those in which the curve is very slight. Crowns 
which are flattened upon either side split in a direction corres- 
ponding with the greatest transverse diameter. A case came 
under my observation in which the cleavage of all the teeth in 
the lower jaw of a large dog was shown in a very marked 
manner. The lower jaw was dried and placed in dilute hydro- 
chloric acid ; decalcification ensued slowly and, finally, the pre- 
viously scarcely perceptible cracks in the enamel became gaping 

* Moh's scale of hardness is the following: 1, talc; 2, gypsum or rock 
salt; 3, calc spar (or any cleavable variety) ; 4, fluor spar ; 5, apatite (crys- 
tallized) ; 6, felspar (any cleavable variety); 7, limpid quartz; 8, topaz; 9, 
sapphire or corundum ; 10, diamond. — Tes. 



30 ANATOMY AND PHYSIOLOGY. 

fissures, extending to the bottom of the crowns. The crowns of 
the incisors w T ere separated into symmetrical median and lateral 
halves, those of the canines, into facial and lingual halves, and 
the coronal denticles of each molar were divided into equal seg- 
ments from their apices to their bases. 

The cracks or fissures, which are observed frequently in the 
enamel during life and are considered at length in the subse- 
quent pages, sometimes occur in the above-mentioned planes. 
The reason for the splitting upon the median line is to be found 
in the symmetrical development of the two halves of the tooth. 

The teeth, together with the bony tissue partially investing 
them, have a high degree of elasticity, in consequence of which 
they may be subjected to marked compression and still return 
to their previous condition upon the removal of the source of 
the latter ; these physical properties appertain to the dentine in 
particular, which, in addition to a solid structure, presents a 
delicacy of texture that admits of a high degree of tension. 

Classification of the Teeth. — The teeth present an enam- 
elled and a non-enamelled portion ; the former is visible in the 
cavity of the mouth, and is called the crown ; the latter is wedged 
in the alveolus and is called the root ; the portion between these 
two is described commonly as the neck. The discrimination of 
the neck of the tooth, however, is more practical than it is 
theoretically correct, since the neck cannot be determined ex- 
cept while the tooth is implanted in the jaw; it is really that 
portion of the root, just above the edge of the socket, which is in- 
vested by the gum. Upon a detached tooth, then, that portion 
may be designated as the neck which is in immediate proximity 
to the terminal border of the enamel. The distinction of this 
portion is of practical importance to the dentist, since he applies 
his instrument to this part in the extraction of teeth. 

The classification of the teeth is based upon their locality, 
duration, and external form. In reference to their locality, the 
teeth are divided into those of the upper and those of the lower 
jaw ; the former being called the upper, and the latter the lower 
teeth. 

The human race is supplied with two sets of teeth : those 
which first make their appearance exercise their functions during 



CLASSIFICATION OF THE TEETH. 31 

a few years only, while the second set is intended for service 
during the remainder of life; hence, in reference to their dura- 
tion, they are divided into milk, temporary or deciduous, and 
permanent teeth. The milk teeth are twenty, and the perma- 
nent teeth thirty-two in number; twenty of the latter occupy 
the places of the previous milk teeth, and are termed permanent 
renewed or substituted teeth, in contradistinction to the tw r elve 
which have no predecessors, and therefore are described as per- 
manent unrenewed teeth. 

It is customary with dentists to divide the permanent teeth 
into four kinds, according to their form, namely: incisors, 
canines, bicuspids, and molars. In anatomical manuals, fre- 
quently only three kinds are distinguished, incisors, canines, 
and grinders or molars; the latter being divided into small and 
large molars. Hunter, however, divided those previously called 
grinders into two kinds, bicuspids and multicuspids, upon ana- 
tomical and physiological grounds, and since that time this 
more rational nomenclature has been adopted by dentists. The 
milk teeth .are divided into incisors, canines, and molars, but it 
is to be borne in mind that the latter differ in respect of their 
construction from their permanent successors, and are to be 
classed rather with the permanent unrenewed molars and, there- 
fore, they are described sometimes by English dentists as tem- 
porary multicuspids or molars. 

The following surfaces are distinguished usually upon the 
teeth : facial (labial or buccal), anterior or external, and lingual, 
posterior, or internal. The contiguous surfaces of adjacent 
crowns receive different names from authors : inner and outer, 
anterior and posterior, medial and lateral, or mesial and distal.* 

Description of the Temporary and Permanent Teeth. — 
It is convenient to commence with the description of the per- 
manent teeth, since, in this way, that of the milk teeth will be 
shortened considerably. f 

* Comp. Tomes's System of Dental Surgery, 1859, p. 38. 

f Carabelli (Anatomie des Mandes, 1841) was the first to make extended 
investigations into the structure of the teeth, with reference to the needs of 
the dentists. E. Miihlreiter has recently published a minute description of 
the human teeth with special reference to the requirements of mechanical 
dentistry. (Leipsic, 1870.) 



32 ANATOMY AND PHYSIOLOGY. 

The i?icisors, considered collectively, present common pecu- 
liarities ; they have, namely, a wedge, or shovel-shaped crown 
and two inclined surfaces which form, by their junction, a 
cutting edge ; the anterior or labial surface is slightly convex, 
the lingual or posterior presents a corresponding concavity ; the 
lateral surfaces are thin and triangular in shape ; the enamel 
cap extends to a greater distance towards the root upon the 
labial and lingual than it does upon the lateral surfaces. The 
cutting edge of the crown in recently cut incisors always pre- 
sents three, more or less prominent eminences, the middle one 
projecting the most. These are short and blunted, and disap- 
pear as soon as the teeth are brought into use. They have 
single roots. 

Upper incisors. — These are larger, more convex upon their 
labial, and more concave on their lingual surfaces, and, in gen- 
eral, have a more rounded form than the lower incisors. Their 
labial surfaces increase in breadth towards the cutting edge, and 
are convex in each- direction. The transverse convexities of 
the teeth upon the right and left side respectively face in oppo- 
site directions, so that the surfaces of the teeth upon the right 
side are directed to the right ; those upon the left side, to the 
left, and in this way the anterior convexity of the dental arch 
is produced. The lingual surfaces present a corresponding 
arrangement of the arches. A pit in the enamel is met with 
frequently in the upper portions of the lingual surfaces, par- 
ticularly of the lateral incisors ; this communicates with a groove, 
and frequently is the seat of the commencement of caries, though 
in this connection it is very likely to be overlooked. 

The crowns of the right and left upper incisors, in addition to 
the above-mentioned arrangement of their arches, are distin- 
guished by their angles. The two angles formed by the junc- 
tion of the gradually narrowing lateral surfaces with the cutting 
edge, are not uniform. Upon the right incisors, the distal 
lateral surfaces join the corresponding incisive edges by means 
of a gentle curve, while the mesial lateral surfaces and the 
edges form sharp right angles. Upon the left incisors the re- 
lations of the angles are exactly the reverse of the latter : hence, 
from these data alone, it is possible to distinguish a right or left 



DESCRIPTION OF THE PERMANENT TEETH. 33 

incisor. Well-formed incisors have single roots, which are coni- 
cal, straight, and afford circular transverse sections. Now and 
then their terminal portions are bent, in which cases the apex 
is directed posteriorly towards the adjacent tooth, i. e., the apex 
of the right central towards the right lateral, that of the left cen- 
tral towards the left lateral, &c. This observation is applicable 
not only to the upper incisors, but to all the permanent teeth. 

The lateral upper incisors present, in general, all the charac- 
teristics of the centrals, but differ from them, however, in the 
gelation of the length to the breadth; while they differ but little 
in length, the breadth of the laterals is a third less than that 
of the centrals, so that the former present a more slender ap- 
pearance than the latter; their edges, moreover, are not so 
sharp, and they are, generally, more rounded than the latter. 

The connection' of the upper incisors with the alveolar pro- 
cess may be shown by means of vertical sections 
through the middle of the tooth and jaw (Fig. 2). 
The anterior or facial wall of the compact process 
is found to be much thinner than the lingual, and 
the latter becomes thicker from below upwards. 

Loiver Incisors. — These are smaller than the 
upper, the convexities and concavities of their sur- 
faces are less decided; they do not present the 
gentle curve at the outer or lateral angle of the 
incisive edge, and consequently lack this element 
of distinction between the teeth of the right and left sides. 
The laterals, moreover, are broader than the centrals, differing 
in this respect from the upper teeth. The side to which a lower 
incisor belongs can only be determined by the curvature of its 
surfaces, which, as observed above, is not very decided, and the 
distinction therefore requires considerable practice. It is more 
difficult to distinguish the centrals than the laterals. The roots 
are single, flattened upon the medial and lateral surfaces, and 
grooved longitudinally. 

* Pig. 2. — Vertical section through the middle of a right upper central 
incisor, showing the connection of the latter with the alveolar process ; be- 
hind the latter appears the incisive canal in an oblique position. Natural 
size. 




34 ANATOMY AND PHYSIOLOGY. 

Canines (dentes cuspidati). — These have a strong club-shaped 
crown, terminating in a point. The labial surface is convex 
and divisible into two equal portions, a medial, more convex, 
directed towards the lateral incisor, and a lateral, more flattened, 
directed towards the first bicuspid. The lingual surface is slightly 
concave, and inclined towards the labial. The lateral surfaces 
of the crown also are convex ; the medial, towards the lateral 
incisor, is moderately arched, the lateral, towards the first bi- 
cuspid, is still more convex, the latter forming a blunt protuber- 
ance. The canines have a single root which is distinguishable 
from the roots of the rest of the teeth in the set by its greater 
length ; the roots of the upper canines are somewhat longer 
than those of the corresponding lower teeth ; the axes of the 
roots describe a slight curve with the convexity directed towards 
the lips. The apices of the roots are inclined more or less 
towards the posterior adjacent tooth. The roots are flattened 
somewhat upon either side and grooved ; the lateral grooves 
upon those of the lower teeth are deeper than those upon the 
upper teeth. The root canals of the upper canines are oval in 
shape, those of the lower are more compressed from either side 
and present a more or less marked incurvation. 

The right and left canine teeth are distinguished by the 
greater arch of the medial halves of the labial coronal surfaces, 
which look toward the lateral incisors, and especially also by 
the curvature of the labial surfaces, which is in opposite direc- 
tions upon the teeth of either side. 

Bicuspids (dentes bieuspidati). — These have crowns essentially 
different from those of the teeth which have already been de- 
scribed. The masticating surface is uneven, and is divided by 
a groove which extends from the front to the back, into two 
pointed tubercles or cusps, of which the outer is the larger. 
The masticating surface of the crown is bounded by four sur- 
faces, which run into one another without forming edges. The 
outer or buccal and inner or lingual surfaces are rounded. 
The lateral surfaces, which comprise the anterior (medial or 
mesial) and posterior (lateral or distal), are somewhat flattened. 
The crowns of all bicuspids are slightly inclined from before 
backwards. The buccal or external surface of the crown of 



DESCRIPTION OF THE PERMANENT TEETH. 35 

each upper bicuspid is indicated by the greater convexity of its 
anterior or medial segment, while its posterior is more flattened 
and inclined, and by the fact that the posterior coronal surface 
is somewhat more convex than the anterior. Their roots are 
more or less flattened, often single, smooth, and frequently are 
traversed in their length by a groove, and sometimes are divided 
more or less deeply at their extremities, this division occurring 
more frequently in the first than in the second bicuspid. 

The crown of the first lower bicuspid resembles that of the 
adjacent canine tooth, inasmuch as the outer or buccal cusp 
projects more than the inner, and hence the masticating surface 
has a more oblique direction toward the median line. The 
second lower bicuspid has a larger, more spherical crown, and 
both cusps are of nearly equal size, so that the first and second 
lower bicuspids may easily be distinguished. The inner cusp 
is sometimes furrowed, giving the appearance of two inner cusps 
with corresponding depressions. Transverse sections of the 
lower bicuspids are oval in shape. 

The masticating surfaces of the upper bicuspids are divided 
by a deep groove extending from before backwards ; the outer 
cusp is somewhat larger and more prominent than the inner, 
which is rounded on the lingual surface. 

Not infrequently the first and second upper bicuspids cannot 
be distinguished when separated from the jaw, but those of the 
right or left side may be recognized by the more decided curve 
of the anterior segment of the facial surface. of the crown, by 
the more flattened and larger posterior segment of the same. 
surface, and by the larger buccal cusp of the crown. 

The molars have a quadrilateral crown, surmounted by several 
tubercles or cusps, and two or three roots. The upper molars 
have irregularly four-sided rhomboidal crowns. The outer and 
inner coronal surfaces are convex, the latter, indeed, to a consid- 
erable degree ; the surfaces looking toward the adjacent crowns 
are flattened. The upper surface is surmounted generally by 
four tubercles or cusps, separated from each other by three 
grooves. One extends from the anterior to the posterior mar- 
gin of the crown, and forms a continuation of the groove upon 
the upper surfaces of the bicuspid teeth. The other two extend 



36 ANATOMY AND PHYSIOLOGY. 

from the middle of the outer and inner margins of the crown 
respectively without coming in contact ; the outer furrow is di- 
rected obliquely forward and the inner obliquely backward, 
forming a flattened bow. In this way four tubercles are formed, 
of which the front pair is the larger. The rhomboidal grinding 
surface presents two acute angles, one directed forwards and out- 
wards, and the second backwards and inwards: and two obtuse 
angles, one directed forwards and inwards, and the other back- 
wards and outwards. The side to which each upper molar belongs 
may easily be determined by observing these angles, together 
with the convexity of the outer surface, and also by the fact that 
the anterior inner cusp is the largest. Sometimes only three 
cusps are observed, at others there are five, and, in the latter 
cases, the larger number is found in the outer row. 

The upper molars have three roots. One springs from the 
inside of the crown and is rounded, while the two proceeding 
from the outside are flattened. The anterior external (facial) 
is broader and longer than the posterior external root. The 
three diverge, and the inner or lingual root is inclined towards 
the palate, while the other two, situated one behind the other, 
are turned towards the outer wall of the jaw. Hence, by the 
arrangement of the roots a right or left upper molar may easily 
be recognized, even without examining the crown. 

An additional cusp sometimes is met with upon the inner 
wall of the crown, which, during the eruption of the tooth, fre- 
quently pierces the gum toward the palate, and gives the ap- 
pearance of the emergence of a second tooth. The first molar 
is the largest, the third, or wisdom tooth, the smallest. The 
cusps of the latter frequently are stunted, and the three roots 
seldom perfect, their development being interfered with from 
want of space. The roots appear, therefore, as if compressed to- 
gether, or are indicated merely by grooves. The roots incline 
backwards. 

The lower molars have a rectangular quadrangular crown 
and only two roots. The upper and lower molars may there- 
fore be distinguished either by their crowns or roots. On the 
upper surface of the first molar are found five cusps, three of 
them in an outer row, two in an inner ; of the three outer, the 



DESCRIPTION OF THE PERMANENT TEETH. 



37 



anterior is the largest, the posterior the smallest, and, therefore, 
by this arrangement of the cusps the crown of a right or left 
first molar can be recognized. On the upper surface of the 
second lower molar there are only four cusps, separated from 
each other by a crucial depression. The wisdom tooth frequently 
presents upon the surface of its crown the crucial depression 
with the four cusps, but quite often they are less distinct, and 
at times merely indicated by the existence of small rounded 
eminences. The outer or buccal are more convex than the 
inner or lingual surfaces of the crowns. 

The two roots of each molar are flattened, grooved, and are 
placed in frorrt and behind respectively. The anterior root is 
broader and longer than the posterior, and in connection with 
the easily recognized external surface of the crown, serves to 
distinguish the right and left teeth. The crowns and roots of 
the wisdom teeth are frequently stunted ; the roots are com- 
monly connate, curve backwards in the form of a hook, and not 
infrequently project into the coronoid process of the lower jaw. 

Transverse sections of the jaw, at the distance of twelve to 
fourteen millimetres from the grinding surfaces of the teeth, 
afford an instructive view of the size, 
form, and position of the separate roots 
in relation to each other. With the 
exception of the lingual roots of the 
upper molars and the frequently cloven 
roots of the first upper bicuspids, they 
have an irregular oblong form, are 
broader on the facial and narrower on 
the lingual side. 

In the upper jaw (Fig. 3), except- 
ing the lingual roots of the molars 
and of the first or second bicuspids, 
all the roots are located quite near to 
the facial wall of the jaw, upon which surface they are broader. 



Fig. 3.* 




* Fig. 3.— Transverse section of the right half of the superior maxillary 
arch, with the corresponding roots and root canals. This case is exceptional, 
since the root of the second bicuspid presents in this section two apices. 
Natural size. 



38 



ANATOMY AND PHYSIOLOGY. 



Fig. 4.* 




' 



The lingual roots of the molars and bicuspids are imbedded in 
the cancellated substance of the bone ; sections of the central 
incisor and the canine have a rounded triangular shape ; those 
of the lateral incisor an oval, and those of the first and second 
bicuspids, before their final occasional division into two apices, 
a biscuit [dumb-bell] shape. If the bicuspids have two deeply- 
notched roots, the buccal root is flattened and presents three 
rounded angles. The buccal roots of the mo- 
lars are convex on the facial side, and con- 
siderably narrower on the lingual side ; the 
lingual roots are nearly circular. In the under 
jaw (Fig. 4) the roots are arranged in a row, 
one behind the other, and are somewhat thicker 
on the facial than on the lingual side, the bis- 
cuit shape predominating. The roots of the 
incisors, canines, and bicuspids, and also the 
larger anterior root of the first molar, are pi 
ed against the facial wall of the jaw ; the smaller 
posterior root of the first molar and the roots 
of the second and third molars are placed in 
the middle of the jaw, equidistant from the 
facial and lingual wall. The compact cortical substance is con- 
siderably thicker, the cancellated substance thinner than in the 
upper jaw. 

The thickness of the roots corresponds exactly with that of 
the crown ; that is, if the crowns are thicker upon one side, then 
the roots upon the corresponding side are also thicker. The 
larger projecting coronal cusps have thicker roots corresponding 
with them, as was observed in the case of the anterior buccal 
roots of the upper molars. The outlines of transverse sections 
of the root canals correspond with those of the roots. 

Temporary Teeth. — These, generally speaking, closely re- 
semble the permanent teeth. A description of the crowns of the 
milk incisors and canines is unnecessary, as the preceding ob- 



* Fig. 4 — Transverse section of the left half of the inferior maxillary 
arch and the corresponding roots and root canals. The posterior root of 
the wisdom tooth is abnormally formed. It should have a hiscui: 
Natural size. 



DESCRIPTION OF THE TEMPORARY TEETH. 39 

servations in reference to the crowns of the permanent incisors 
and canines are equally applicable to those of the former. The 
milk teeth with single roots can only be distinguished from the 
corresponding permanent teeth by the generally roundish roots 
of the former and by their inclination in a direction opposite to 
those of the permanent teeth. 

The deciduous molars alone deserve particular consideration. 
With children these teeth take the place of the permanent or 
true molars, and have the same general form. The first decidu- 
ous molar resembles the permanent bicuspid in form, while the 
second is an exact counterpart of a permanent molar. It is 
hardly necessary, therefore, to mention that the first molar is 
smaller than the second. 

The first upper milk molar has a broad crown, is flat upon 
the anterior (medial) and posterior (lateral) surface, while the 
external and internal surfaces are convex. Projecting forward 
from the anterior half of the outer surface, near the neck of 
each tooth, a prominence is found, by means of which also they 
may always be recognized. The grinding surface presents two 
cusps, separated by a longitudinal groove, one of which is on 
the outside, the other on the inside. 

The crown of the second upper molar has, on a smaller scale, 
exactly the form of the first permanent molar. All the upper 
molars have three roots, the position and shape of which corres- 
pond exactly with those of the upper permanent molars, except 
that the former are more divergent than the latter. 

The lower deciduous molars have more elongated crowns, 
that of the first resembling somewhat that of a permanent bi- 
cuspid, while that of the second is very similar to the crown of 
the first permanent molar. The first are characterized further 
by a protuberance found on the outer surface of the crown, and 
by two small depressions on the grinding surface, of which the 
first is the smaller, both being surrounded by elevations of en- 
amel. Upon the grinding surface of the second, the cusps are 
more distinct, and frequently five in number, three on the outside, 
and two on the inside, the anterior external one being the largest. 
The lower teeth, like the lower permanent molars, have two flat- 



40 ANATOMY AND PHYSIOLOGY. 

tened widely separated grooved roots, each of which is formed, 
as it were, by the blending together of two contiguous roots. 

The distinctions between the milk and permanent teeth are 
found principally in their color, form, and size. The milk teeth 
present, even externally, the indications of a more delicate tex- 
ture. They have a much whiter, even milk-white, color, and 
as the period for their detachment approaches, a bluish-white 
color. On the other hand, permanent teeth, particularly when 
they first appear, are of a yellowish shade, which passes into a 
decided yellow near the gum. This difference is much more 
noticeable if a milk tooth happens to be next to a lately cut per- 
manent tooth. Milk teeth, as before stated, are also smaller in 
all their dimensions as they are placed in the still undeveloped 
jaws of childhood. Permanent teeth, when first cut, have quite 
as broad a crown as in later life, and therefore the difference in 
size between them and the milk teeth is much more striking. 
The cutting edges of the permanent incisors, as before stated, 
are divided into three blunted denticles, by two notches : two 
shallow grooves also traverse the labial surfaces of these teeth, 
disappearing gradually toward the necks; these denticles and 
grooves can be seen only in young incisors, for they disappear 
from attrition in the course of a few years. These are also 
present in young milk teeth, but as they immediately wear away, 
their absence affords a quite positive basis of distinction between 
milk and young permanent teeth. One of the most notable points 
of distinction between the teeth of the two sets is afforded by 
the fact that the milk teeth, at the period of shedding the teeth, 
are considerably worn away, while the new teeth have very 
sharp edges and eminences. The roots of the deciduous molars 
diverge considerably, because they include the crowns of the 
permanent bicuspids between them, like a pair cf tongs. 

Arrangement of the Permanent Teeth. — In their normal con- 
dition, the two rows of teeth form two arches, lying one above 
the other, with their convexities directed forwards and their 
concavities backwards. When the mouth is closed the bicuspids 
and molars of the two rows are situated in the same perpen- 
dicular planes ; the upper incisors and canines, on the contrary, 
are directed somewhat obliquely forwards, in a direction oppo- 



ARRANGEMENT OF THE PERMANENT TEETH. 



41 



site to that of the corresponding lower teeth, and project slightly 
beyond the latter. The intervals between the upper and the 
lower central incisors, and the two frcena lahiorum are in the 
median line. 

The upper row of teeth forms a quite uniform, nearly semi- 
elliptical arch, with its posterior extremities drawn towards each 
other, while the lower teeth form a parabolic curve, narrower 
in front, the arms of which diverge posteriorly. The upper in- 
cisors, as a whole, are broader than the lower, and the upper 
canines also include a larger space than the lower, consequently 
the right anterior upper teeth do not stand directly over the 
corresponding lower ones, but the central upper incisor covers 



Fig. 5.* 




the whole of the edge of the opposite central and the medial 
half of the lateral lower incisor. The upper lateral incisor 
covers the distal half of the lower lateral incisor and the medial 



* Fig. 5. — A well-developed set of permanent teeth, projected upon a 
plane in order to show the mutual relations of the upper and under teeth 
and the curve described by the upper and under rows of teeth. Facial view. 
The first five teeth in this case project over the under ones in a decreasing 
proportion, that is, the first upper incisor projects the most, and the second 
upper bicuspid the least ; each of these five teeth also overlaps the tooth ad- 
jacent to its immediate opponent. The size of the crown of the first lower 
molar is such that the crowns terminate on the same line. Natural size. 



42 



ANATOMY AND PHYSIOLOGY. 



half of the canine. The upper canine tooth is inserted between 
the lower canine and first bicuspid ; the first upper bicuspid be- 
tween the first and second lower bicuspid. But as the second 
upper bicuspid has a narrower crown than the first, while the 
reverse is true of the lower bicuspids, it is found usually that 
the first upper molar stands directly over the lower, and is in 
relation with only a slight portion of the edge of the second 
lower molar. Finally, as the upper wisdom tooth is generally 
smaller than the lower, it results that the complete dental arches 
are equal in length. Variations are of frequent occurrence. 

The incisive edges and masticating surfaces of the two rows 
of teeth form serpentine curves which correspond with the pre- 
viously mentioned wavy outlines of the margins of the alveolar 



Fig. 6.* 




processes, and are conformable to the variations in the lengths 
of the crowns. In the upper jaw this curve presents convexi- 
ties downwards in the middle of the two lateral portions, corres- 
ponding to concavities directed upwards in the lower jaw. while 



* Fig. 6. — A well-developed set of deciduous teeth, together with the 
crowns of the permanent teeth inclosed in their capsules, projected upon a 
plane. The three anterior upper milk teeth project over the lower ones. The 
upper canine overlaps the lower one somewhat posteriorly. As the crowns 
of the upper are smaller than those of the lower molars, the second molars 
terminate posteriorly upon the same line. The curves described by the upper 
and lower rows are evident, but are less marked than in the permanent 
set. Natural size. 



THE HARD TISSUES OF THE TEETH. 43 

the converse is true of the relations presented by the arches of 
the anterior portions of the jaws. 

In the further description of the dental arches it may be men- 
tioned that a single sharp edge extends along the summits of 
the three front teeth, while upon the bicuspids and beyond it is 
double and is formed by the two rows of cusps. Between these 
two rows a shallow groove extends backwards. 

Generally the crowns diminish in length from before back- 
wards, so that the incisors project the most, the wisdom teeth 
the least, from their sockets. 

The arrangement of the milk teeth differs from that of the 
permanent, inasmuch as the second molars terminate the rows 
of the former posteriorly, and the deciduous molars generally 
have larger crowns than the permanent bicuspids. The three 
upper front teeth project over the lower to a comparatively less 
degree (Fig. 6). 

The Hard Tissues of the Teeth. — Human teeth are com- 
posed of three separate tissues; the dentine (tooth-bone) consti- 
tutes the principal mass, while the remainder is composed of 
the enamel, which forms a covering for the crown, and the 
cement, which covers the root. 

The dentine, ivory or tooth-bone, forms the principal part of 
the tooth, and gives to it its form, so that the different kinds of 
teeth may easily be recognized, even after the separation of 
the enamel and cement. Comparative histology also illustrates 
this fact, for in tracing back teeth of the animal kingdom to a 
rudimentary form in the order of their development, the den- 
tine is found to occur earlier than the enamel and cement. 

The dentine presents for consideration a peripheral or outer 
surface, which is in relation with the enamel and cement, and 
an inner surface which incloses the pulp-cavity or root canal, 
and has an organic connection with the pulp. 

The elements which characterize the dentine are the den- 
tinal canals or tubes imbedded in the basis-substance, which 
ramify in various directions from the inner surface toward the 
periphery. These canals gradually become more narrow as they 
approach the periphery and everywhere pursue a wavy course. 
In its course the principal canal divides dichotomously, at an 



44 ANATOMY AND PHYSIOLOGY. 

acute angle, into branches which also subdivide at regular in- 
tervals. At uniformly short distances from the periphery of 
the' dentine the canals are divided into numerous minute 
branches; but throughout the entire course of the main tubes 
and their branches there occur also at short intervals quite 
numerous twig-like branches which ramify in various direc- 
tions, in some cases forming transverse and oblique anastomoses 
with the neighboring canals, in others, connecting with each 
other by means of sharply curved loops. According to "Welcker* 
the dental canals pursue a spiral course. 

In order to obtain a definite idea of the great multitude of 
secondary branches, a thin section should be placed in pure 
Canada balsam, or slightly macerated in very dilute hydro- 
chloric acid, when the delicate tubules, divided transversely and 
obliquely, will be brought clearly into view. Under very high 
magnifying powers the macerated portions present a foveated 
or honeycombed appearance. The question whether the fine 
tubules also terminate in free extremities within the basis-sub- 
stance is difficult to determine. It is quite probable, however, 
that they form an inclosed system, from the fact that clearly 
defined anastomoses are so numerous. 

Formerly the canals were considered to be mere cavities, 
through which circulated a fluid containing calcareous salts 
in solution, and an analogy was drawn between them and the 
canals of bone. Since, however, J. Tomesf has shown that 
each dentinal tubule is tenanted by a soft fibre, this earlier im- 
pression must be abandoned. t 

* Zeitschr. fur rationelle Med. N. F. Bd. viii. 

f Phil. Trans., v. 146. 

J E. Neumann (Beitrage zur Kcnntniss des normalen Zahn- mid Knochen- 
gewebes) maintains the existence of special calcareous sheaths of the den- 
tinal fihres. These he calls dentinal s/tcat/ts. and he asserts that they may 
he isolated, while ne bases his opinion upon the ground that maceration or 
incineration destroys the fibres, and that the felted mass of filaments, which 
remains after the destruction of the basis-substance by means of hydro- 
chloric acid, must be regarded as the persisting sheaths of the fibres. The 
correctness of this theory of the destruction of the fibres by maceration or 
by incineration I am inclined to doubt, until a distinction is established be- 
tween the fibres presented in a non-maeerated specimen of dentine and 
those which are isolated in one which has been subjected to the process of 



THE HARD TISSUES OF THE TEETH. 45 

The intertubular or basis-tissue of the dentine is so generally 
traversed by the dental canals that it is difficult to make a proper 
morphological analysis of it. It has the appearance of a homo- 
geneous substance, with a double refractive power, which, after 
the extraction of the calcareous salts by means of hydrochloric 
acid, furnishes an organic residue resembling ossein, the so- 
called dental cartilage, which also possesses the property of 
double refraction. Whether the calcareous salts are present in 
the dentine in a crystalline form is a question upon which 
hardly anything is determined as yet. If a section of a tooth, 
that of a horse for example, be very slightly and carefully 
treated with acids, fine markings, perpendicular to the canals, 
are brought into view which may possibly imply such a con- 
dition. 

The globular masses or dentinal globules are composed of an 
agglomeration of transparent, resisting, spherical bodies of vari- 
ous sizes, which, particularly with very young persons, occur 
upon the inner wall of the dentine; as a rule, also, upon its 
periphery, and almost always, to a greater or less degree, be- 
tween the dentinal laminae, and, therefore, may be designated 
as inner, outer, and intercalary globular masses. Where several 
dentinal globules are contiguous, they inclose a jagged space, 
Czermack 's interglobular space, which is filled with a substance, 
visible to the naked eye and called interglobular substance. 
The latter, with its jagged periphery, might be mistaken for a 
bone-corpuscle ; on more careful examination, however, it will 
always be seen that the delicate ramifications of the bone canal- 
iculi are wanting. 

The dentinal canals are not everywhere uniformly arranged, 
but are separated more or less into larger or smaller groups by 
a homogeneous basis-substance, or by globular masses. The 

maceration. The view which seems to me most plausible is that the den- 
tinal fibres consist of a cortical, more dense, and a central vitreous sub- 
stance, which latter dries up as soon as it is exposed to the air, so that the 
dentinal tubules become filled with air. The familiar luminous ring which, 
in transverse sections, is seen to surround the dentinal canals, and upon the 
theory of the existence of an isolable sheath, is interpreted as a calcareous 
dentinal sheath, in my opinion, is to be regarded as a homogeneous basis-sub- 
stance, which invests the dentinal tubes like a sheath. 



46 ANATOMY AND PHYSIOLOGY. 

directions of the canals are often very plainly perceived in cross 
sections of the neck, and correspond with the laminated structure 
of 'the dentine. The globular masses inserted between the 
laminae are often found in great abundance in otherwise per- 
fectly normal human or animal teeth, and are then to be con- 
sidered as evidences of interruptions in the regular process of 
development. Under the head of Pathology will be found a 
further consideration of the question, whether the globular sub- 
stance represents a primary stage in the development of the 
dentinal tissue (globular formation), or an osseous tissue. 

Comparative history furnishes two other dentinal formations 
which may be alluded to in this connection, though their con- 
sideration is included under the head of Pathology. They are 
the so-called vaso-dentine and osteo-dentine of R. Owen, de- 
scribed in his " Odontography." The first is characterized by 
a system of cylindrical vascular canals which, like the Haver- 
sian canals of bone, traverse the dentine and are connected 
with the bloodvessels of the pulp. The osteo-dentine is observed, 
generally, upon the surface of the pulp-cavity and seems to be 
a combination of irregular dentine with more or less accurately 
defined osseous tissue. 

The enamel forms a hood-like investment of the coronal portion 
of the dentine, and is composed of a very hard, brittle substance 
which is thickest upon the edges of the incisor teeth, and upon 
the cusps of the others, is less thick where it forms a lining to 
the coronal depressions, and becomes gradually thinner towards 
the commencement of the root, where it terminates abruptly, 
and is slightty overlapped by a rudimentary layer of cement. 

The outer exposed surface of the enamel is everywhere 
smooth normally, but the inner surface, on the contrary, which 
unites with the dentine, presents-every where slight irregularities. 
Upon the external surface, particularly in the teeth of young 
persons, and most plainly upon the labial surfaces of the front 
teeth, delicate ridges may be seen with a lens, running trans- 
versely, and separated from each other by tolerably equal 
intervals. 

In the teeth of older people, or in those where the enamel is 
not regularly developed, these lines or ridges are less distinctly 



THE HARD TISSUES OF THE TEETH. 47 

or only partially visible, and sometimes are entirely impercepti- 
ble ; the lingual surfaces of the enamel have, usually, the more 
polished appearance. In order to examine the dentinal surface, 
it is best, as recommended by Giebel, to corrode the dentine by 
a boiling fifty per cent, solution of sulphuric acid, by which 
means the enamel cap may be detached. If now the inner sur- 
face of the dried cap be examined under a sufficiently high 
magnifying power and with reflected light, a series of diminu- 
tive rounded elevations will be perceived. 

The thickness of the enamel varies in the different kinds of 
teeth. On the front ones, it is somewhat thicker on the labial 
than on the lingual surface, measuring on the incisors nearly 
one millimetre, and on the canines somewhat more ; on the bi- 
cuspids and molars the enamel is thicker than on the front teeth, 
and is thickest on the first molars. It attains its greatest thick- 
ness at the summits of the cusps, where it measures two, some- 
times even three millimetres. The thinning of the enamel 
towards the roots is quite gradual on the front teeth, while on 
the back ones it terminates somewhat more abruptly, and pre- 
sents a proportionately rapid increase in thickness. 

The elementary organs of the enamel are calcified, cylindrical 
cells, blended together in their long diameters, so as to present 
the appearance of striated fibres — the so-called enamel fibres ; 
in transverse sections, they present a polygonal appearance, on 
account of their being packed closely together, but occasionally 
are more or less rounded. These longitudinal chains of calcified 
cells are united into bundles which pursue a wavy course and 
decussate one with another. Therefore, in longitudinal and 
transverse sections of the enamel cap, longitudinal, transverse, 
and oblique sections of the enamel cylinders (enamel prisms) are 
met with. 

Isolation of the enamel fibres may easily be effected by means 
of dilute hydrochloric acid. The fibres becoming swollen and 
varicous, present on the depressed portions an apparent trans- 
verse striation, and between the opposing contiguous portions, 
narrow fissure-like intervals remain which have given rise to the 
view entertained by some investigators that canals are found in 
the enamel. The appearances presented by a section in which 



48 ANATOMY AND PHYSIOLOGY. 

the fibres pursue a longitudinal course are particularly deceptive : 
but with careful examination these intervals cannot be con- 
founded with canals, for it will be seen that they have no branches 
and cannot be isolated. The intervening substance between the 
enamel fibres is transparent normally, but, in frequent anoma- 
lous conditions it presents, in many places, a foraminated, indis- 
tinctly granular appearance. 

The calcareous salts are deposited in the enamel fibres in a 
crystalline form. If a very thin section of enamel be treated 
with largely diluted hydrochloric acid, the edge will be seen to 
become uniformly indented, and, as the action of the acid con- 
tinues, a precipitation of acicular crystals ensues, which imme- 
diately redissolve. If cross sections of the enamel fibres are 
carefully examined after a slight action of the acid, they will 
appear to be filled with angular grains, which also are the 
needle crystals of phosphate of lime in transverse sections. 

It is difficult to generalize the direction and grouping of the 
enamel fibres. They vary in different kinds of teeth and differ 
in the same tooth in accordance with the varieties in its forma- 
tion. The fibres are of unequal length and thickness, and are 
collected together into bundles which decussate with each other 
so as to present in many places a felted mass. If sections in 
the longitudinal axes of the crowns of the incisors are examined, 
it will be seen that entire bundles which have fallen within the 
section are separated from each other by uniform intervals, 
while the latter are occupied by those which are cut across 
transversely and obliquely. A similar relation, in respect of 
arrangement, prevails throughout the entire enamel, and is more 
distinctly displayed in sections corresponding with the longi- 
tudinal axes of the coronal cusps of the bicuspids and molars. 
The fibres of the latter, however, in those portions where the 
enamel becomes thinner, not infrequently assume a parallel di- 
rection. The decussation of the bundles also affords an expla- 
nation of an optical phenomenon which is presented when such 
a longitudinal section of enamel is examined under the lens by 
means of very oblique reflected light, and with a dark back- 
ground. Under such circumstances the transversely divided 
bundles are presented in the form of luminous striae, while those 



THE HARD TISSUES OF THE TEETH. 49 

which are seen in their long diameters have an opaque appear- 
ance. The converse view is obtained with transmitted light. 
If we examine an entire set of teeth, it will he found that de- 
cussations of the bundles are most marked in portions corres- 
ponding to the papillary projections, a fact readily understood 
when it is considered that the directions taken by the formative 
enamel cells in their growth vary the most in localities where 
the greatest curvatures occur. 

Transverse sections of enamel present a series of striatums 
which follow concentrically the contour of the dentine. They 
are curved like a bow, are sharply defined, nearly equidistant 
from each other, and may be regarded as probably only an ex- 
pression of the laminated mode of formation of the enamel. 

The enamel of the teeth of young persons is transparent in 
thin layers, and of a yellowish color. The color, however, 
presents numerous varieties which bear a certain relation to 
the durability and hardness. As a rule, it may be said that 
yellowish enamel is the most durable ; its fibres also are more 
uniformly disposed. In this connection it would be well to as- 
certain whether the organic matters are not more abundant in 
the latter enamel than in other forms. A very durable en- 
amel, has a uniformly dense, resisting texture, a smooth surface, 
offers considerable resistance to the action of a file, and has a 
certain degree of transparency. The enamel of whiter teeth 
generally is of more moderate strength, breaks more easity, and 
contains perhaps less organic substance. In teeth of chalky 
whiteness, it is often thicker and crumbles easily. In such cases 
the enamel contains an opaque granular mass which renders the 
recognition of its fibres impossible. Bluish-white teeth are the 
most delicate, and have a thin layer of enamel. Less durable 
enamel is of an irregular, less compact texture, which offers less 
resistance to the file, and with transmitted light thin sections 
of it are often clouded by dark spots, which appear white with 
reflected light. 

Enamel frequently contains light or dark brown deposits of 
pigment. In the teeth of animals, this brown discoloration is 
observed sometimes towards the periphery of the enamel, at 
other times internally, near the dentine, and even the fibres are 

4 



50 ANATOMY AND PHYSIOLOGY. 

impregnated with the coloring matter. The enamel of human 
teeth, also, contains light and dark brown pigment without the 
least trace of cohesion of the particles. The dark pigment is 
found also in the limiting or cortical substance of each enamel 
fibre, in consequence of which a transverse se'ction of the latter 
presents the appearance of a circle of pigment. This cortical 
pigmentary deposit in the enamel fibres not infrequently reaches 
only to a certain depth in the layer of each fibre, and to this 
circumstance is to be ascribed the fact that the concentric striae 
are more distinct in enamel containing pigment. 

Enamel, as is well known, has a property of double refraction, 
which has recently been investigated by Hoppe-Seyler.* When 
fully developed, it exhibits negative double refraction, and 
positive while its development is in progress. By heating to 
800°, the negative refraction becomes positive. Cross-sections 
of the prisms present no double refractive power. 

The junction of the enamel with the dentine is effected by 

a transparent, irregularly wavy, 
»..,... tl t -n .femia^ boundary layer which, in some 

P^^^^S^^^^H parts, is encroached upon by sep- 

arate dentinal canals (Fig. T), and 
-6 in others by elongated cleft-like 
^^SSr^^ cavities, of irregular shapes and 

=^_ . . different dimensions. Into these 

cavities, which are mostly filled 
with opaque, amorphous calcareous 
masses, one or another of the den- 
tinal canals frequently enters. 
Sometimes, though quite rarely, a terminal loop is seen in the 
hyaline boundary layer. These cavities penetrate more or less 
deeply into the enamel, and are found most commonly in parts 
corresponding to the incisive and masticating portions of the 

* Yirchow's Archiv, Bd. 24. 

f Fig. 7 shows the line of junction between the dentine and enamel in a 
longitudinal section of an incisor. The enamel fibres are divided, partly in 
their longitudinal axes (a), and partly in a transverse direction (*). The 
boundary layer is irregularly wavy. The dentinal canals [c) present vory 
delicate branches, which ramify toward the bordering layer. Magnified 
500 diameters. 



CEMENT. 51 

crown. Usually they run obliquely to the direction of the 
enamel fibres. They seem to occur more frequently in the 
teeth of elderly people, in which the crowns have been worn 
away partially by attrition. 

If we take into consideration these circumstances, viz., the 
encroachment of the dentinal canals upon these bounding layers, 
the occurrence of oblong cavities inclosing dentinal canals, the 
penetration of these cavities only to a certain depth into the 
enamel, and their more frequent occurrence in old age, I think 
there is ground for considering this bounding layer, which be- 
comes more evident in the teeth of larger mammals, as belonging 
to the dentine, and therefore for regarding the cavities as results 
of resorption of the dentine rather than of defects in the devel- 
opment of the enamel. If the crown of a tooth be subjected to 
the action of very dilute hydrochloric acid for about twenty-four 
hours, the delicate membrane, first observed by Nasmyth (J¥as- 
mytlis membrane), will be detached. It may, however, even 
without the employment of acid, be demonstrated by suitable 
sections of the enamel, as a transparent layer with a sharply 
defined exterior. The detached membrane is smooth upon its 
exposed surface ; upon the internal surface, it is connected with 
the enamel fibres, between the rows of which it sends processes, 
and hence it presents, in many places, an impression as it were 
of the contiguous portions of the rows of enamel prisms. In 
the disposition of the pigment in the periphery of the enamel, 
these impressions become still more distinct. Kolliker. who 
designated the membrane the "cuticle of the enamel," found 
that it remained unchanged in boiling water and mineral acids. 
Waldeyer states that, when boiled with caustic potash or soda, 
it becomes softened ; and when burned, it yields an odor resem- 
bling that of burnt horn. He was unable to detect any lime 
in it. 

Cement. — This forms an osseous covering, shaped like a 
sugar-loaf, of the root portion of the dentine. It is thickest at 
the apex and gradually becomes thinner towards the so-called 
neck of the tooth. At the apex of each root it is reflected 
toward the internal surface of the canal of the root, upon the 
outermost portion of which it is disposed. 



52 ANATOMY AND PHYSIOLOGY. 

The external surface of the cement, in many young teeth 
which perhaps are quite normal, presents delicate transverse 
strjations, which, to the naked eye, resemble the striations which 
may be seen upon the surface of the enamel. In other normal 
teeth, this surface is more polished or marked by very slight 
elevations and depressions which become more decided near the 
extremities of the roots. 

Sections of normal cement, in which the outer surface is pre- 
served intact, show that a mass of minute nodules, which i 
be termed the external calcareous-granular layer, forms the 
outermost stratum, directly beneath which appear the bone-cor- 
puscles. This layer has an organic connection with the perios- 
teum of the root or root membrane, and, as the development of 
the cement proceeds from the latter, this laver-is to be regarded 
as representing the primary stage in the formation of the cem< 
analogous to the layer of dentinal globules on the inner surface 
of young dentine. 

In the thicker portions of the cement the bone-corpusch 
disposed in numerous layers, one over another, which snl 
quently pass into a single row, and finally disappear altogether. 
They differ from true bone corpuscles, inasmuch as thev 
generally somewhat larger, present a greater number of radia- 
tions, and a greater diversity of form and arrangement. The 
very numerous canaliculi given off from them im media! 
divide into branches at very acute angles, the two together | 
senting a tuft-like appearance. Sometimes the canaliculi 
radiate from the bone-corpuscles in parallel rows, and extend a 
considerable distance without forming a network. The form of 
these bone-corpuscles varies, being spindle-shaped, round 
triangular or polygonal, pyriform, &c. Their arrangem 
also varies, the long axes of the elongated ones being parallel 
with sometimes, and at others perpendicular to that of the root 
of the tooth. Some are met with closely packed, one upon 
another, as it were blended together, and'others which are far 
apart, and between the latter a considerable amount of inter- 
corpuscular substance is inserted, which sometimes occupies the 
entire field of view. This latter, particularly in the cement of 
old teeth, presents a finely lamellated structure, which mav 



JUNCTION OF THE DENTINE AND CEMENT. 53 

demonstrated by means of very dilute hydrochloric acid, or, still 
better, lactic acid. The thickness of the lamellae, in portions 
adapted for observing them, is so slight as to be immeasurable, 
when viewed by ordinary methods, and they resemble the 
regular lamellation presented by the agate. In other parts the 
basis-substance is generally diffused, molecular or vitreous, 
homogeneous. 

At the periphery of the teeth of old people, in which the 
cement everywhere, but especially near the apices of the roots, 
is thicker than in those of younger persons, bone-corpuscles are 
met with not infrequently, one, two, or more of which are in- 
vested by a clear, highly refractive layer. The radiation of the 
canaliculi takes place within this bounding layer, which presents 
a lobulated appearance when it incloses several corpuscles. 
This condition of the osseous substance evidently corresponds 
with a developmental stage, an interstitial growth, in which the 
resorption of the envelope of the bone-corpuscles has not yet 
taken place. Vascular canals frequently occur in the cement 
of old teeth, and at the extremities of the roots of younger teeth, 
also, one or another may be found extending from the surface 
of the cement through the dentine to the root canal. 

If the cement be traced upwards towards the crown of the 
tooth, its transition into a mere rudimentary osseous substance 
may be observed. The separate rows of bone- corpuscles disap- 
pear and are succeeded by minute irregular cavities. The most 
striated portion of the basis-substance of the osseous tissue con- 
tinues its course alone, and, decreasing in thickness toward the 
attenuated border of the enamel, it projects over the latter for 
a short distance. At this part, therefore, the hard tissues of 
the teeth, cement, enamel, and dentine, are joined together. 

The dentine and cement are connected together by means of 
a layer composed of an agglomeration of transparent globules, 
and of varying degrees of thickness. The spaces intervening 
between the latter (interglobular spaces) are irregularly notched 
and frequently in very close proximity to one another ; they 
are filled with an opaque, granular, calcareous substance, and 
very often are in direct connection, on one side with dentinal 
canals, and on the other side with the bone-corpuscles of the 



5_J. ANATOMY ANP PHYSIOLOGY. 

cement. Sometimes this intermediate layer is very finely 
granular, and the spaces between the grains are exceedingly 
small. The cement proper commences outside of this layer, 
and its canaliculi rarely come into direct connection with the 
dentinal canals. 

The Dental Pulp occupies the cavity of the crown and the 
canal of the roots of each tooth, and is the persisting g< 
bed of the dentine, its organ of nourishment and 
Its exterior corresponds with that of the tooth, so that if it 
isolated completely, its appearance alone will indicate to which 
kind of tooth it belongs. 

The pulp is divided into the crown and radical portion. The 
former is provided with one, two, or more. conical pi 
which correspond with the tubercles upon the summit of the 
crown, and divides into as many radical port': are 

roots. The lengths of the conical pro : the pulp bear a 

direct relation to the height of the coronal cusps, and 1 
the pulps of the incisors they are barely discernible as thi 
pointed elevations. The thickness of the pulp 
with the exterior of the tooth, that is, the relatively thicl 
coronal portions are found in the canine and n the 

radical portions are flattened within the compr< 
With young persons the pulps are thicker than with tl 
and they decrease in thickness as age advances. The pu 
smooth upon its surface, of a yellowish, reddish-yellow, 
deep blood-red color, corresponding with the blood which it 
tains ; its transparency is such that the course of the \ 
distinctly perceptible at the margins ; its 
like that of young, succulent connective tissu 
with the dentine, particularly in young teeth, is formed by a 
delicate, lax tissue. The outer surface of the pulp is 
with conical cells, the dentinal cells [odontol From the 

broad faces of which, directed outwards, comparatively thick 
processes extend. Boll* observed several pr< 
from a single cell towards the dentine, and also short lateral 
ones which connected adjacent cells. 

* Archiv fur mikr. Anat.. iv. 



DENTAL PULP. 



55 



Fig. 8. 




The dentinal processes enter the contiguous dentinal canals, 
and, like the latter, divide into branches 
and numerous ramifications. The pro- 
toplasm of the cells is finely granular, 
and the nuclei are oval. A more slender 
process, which occasionally divides, ex- 
tends internally from these cells and dis- 
appears in the connective tissue, or is 
united with a spindle-shaped nucleated 
cell, which latter indeed is to be regarded 
as a formative cell, cell of repair (Ersatz- 
zelle) (Fig. 8). 

The basis-tissue of the pulp consists of 
a loose connective tissue containing scattered connective-tissue 
cells of various forms, among which the spindle shape predomi- 
nates. Bundles of wavy connective tissue serve to give it firm- 
ness, while it is totally destitute of the elastic element. In aged 
persons the pulp is more dense and tenacious, and contains, also, 
a larger quantity of fibrillated connective tissue. 

The bloodvessels are very abundant ; several main trunks 
enter and leave the pulp, and in the root portion, partly also 
in the crown, pursue a straight course for the most part. 
Transverse sections of the pulp give a good idea of the multi- 
tude of the vessels and their respective distances from each other 
(Fig. 9). The wider vessels are found internally, where their 
ramifications present a bushy appearance. The sharply-curved 
terminal loops of the capillaries are found everywhere beneath 
the layer of dentinal cells, and are grouped in a manner simi- 
lar to that presented by the ramifications of the vessels in the 



" :: " Fig. 8. — Transverse section of the marginal portion of the pulp from 
the tooth of a colt. The dentinal cells, arranged side by side, present, at 
their peripheral extremities, free, elongated, thick processes, which have 
been isolated from the dentine; the former contain within their finely 
granular protoplasm one or two oval nuclei, in close proximity or at a dis- 
tance from each other, present a sort of annular constriction and, internally 
at thoir pointed extremities, are in relation with the connective-tissue cor- 
puscles of the parenchyma. The cavities of numerous bloodvessels, divided 
transversely and obliquely, appear in the section. Magnified 400 diameters. 



56 



ANATOMY AND PHYSIOLOGY. 



Fig. 9 * 



papilla of the tongue. Lymphatic vessels have never been 

demonstrated in the pulp. 
-The nerves of the pulp are extremely numerous, and are 

united into several bundles, the latter forming a network of 
ramifications in the body of the pulp. 
They extend in the neighborhood of blood- 
vessels, and the manner of their disp 
tion may be demonstrated by cross-sec- 
tions of the body of the pulp (Fig. 9). 
The primitive nerve-tubes are quite ratal] 
in diameter. We are enabled through tbe 
researches of Czermak ami II. Miiller to 
recognize portions of the latter: but the 
delineation of the exact mode of their 
ruination is attended with extreme diffi- 
culty. Bollj observed the transition of 
dullated (markhaltig) into nuiner 
medullated (marklos) nerve-1 bich 

latter also gave off very delicate bran 
between the dentinal cells. Whether these actually enter the 
dentinal canals remains undecided.^ 




* Fig. 9 —Transverse section of the pulp ofn canine tooth 
tinal cells with their isolated, elongated pro 

nerve-tubes and (c) capillaries divided transvers >f the 

vessels increase in diameter towards the central portion of the p 
network of connective-tissue bundles forms the stroma. Magnifl 
diameters. 

f Loc. cit. 

I We know, from the clinical observations of J. Tomes, that the 
surface of the dentine is remarkably sensitive to the action of mecl 
and chemical agents, and that the same is true of the inner port 
to a less degree. As soon as the pulp is destroyed, the - of the 

dentine ceases. J. Tomes concludes from this fact that the - 
the dentine depends upon its connection with the pulp, and that it- 
hard tissue possesses no inherent sensitive properties. He is pinion 
that the sensitive properties of the dentine are due to the solid dentinal 
fibres which formerly were thought to be tubes, and it s«.-ems to him by no 
means necessary to assume that these fibres are actual nerves. He 1 
ceeded no better than others in proving a connection between dentinal and 
nerve-fibres. The anatomical reasons for the sensitiveness of the dentine 
remains, therefore, a postulate. 



GUM. 57 

The Gum is that portion of the mucous membrane of the 
mouth which surrounds the alveolar margins of the jaw. It is 
closely adherent to the necks of the teeth and is distinguished 
by several peculiarities. It is divided into a labial (external) 
and lingual (internal) portion, and the curved laminae which 
arch transversely in the intervals between the teeth. It is of a 
pale flesh color, attenuated, has a glittering appearance and a 
compact structure. Two layers of the gum require particular 
consideration, viz , the papillary portion with the epithelium, 
and the submucous connective tissue. The latter is intimately 
connected on the one hand with the periosteum of the bone, and 
on the other with the root membrane (periosteum of the root). 
The papilke, situated upon* its surface, are finger-shaped pro- 
longations of the corium of the mucous membrane, which are 
arranged in rows. In different portions, and in different in- 
dividuals presenting apparently normal gums, many variations 
occur in respect of the size and manner of grouping of the 
papilhe. For example, in somewhat swollen gums particularly, 
groups of several papillae may be seen arising from a common 
base, or a main stem may divide into secondary ones from which 
corresponding papillary groups arise. The structure of these 
papillae can be demonstrated properly only after the removal of 
the epithelium. The outer homogeneous layer of connective 
tissue (lining [basement] membrane), under very high magnify- 
ing powers, presents minute indentations, which serve for the 
reception of the analogues of the aculeated or furrowed cells of 
the Malpighian layer. In the body of the papilla lie fusiform, 
sometimes rounded, connective-tissue corpuscles situated at 
regular intervals, the long axes of the spindle-shaped ones cor- 
responding with the curve of the papilla, while in the lower 
part of a papilla the direction of their long axes becomes more 
horizontal. In the very firm submucous connective tissue of 
the gum, delicate elastic fibrils also are found, while they are 
wanting, as a rule, in the papillary portion. 

The bloodvessels are very numerous, and the relatively large 
arterial and venous trunks pursue a more or less horizontal 
course at the base of the papillary portion, where the afferent 
and efferent branches are given off towards the papillae. The 



58 



ANATOMY AND PHYSIOLOGY. 



an 



Fig. 10. : 




final division of the branches takes place, generally, at the 
ole of junction of two papilla (Fig. 10). Each papilla con- 

tains but one anastomotic loop 
which pursues an ondulatory 
course. In elongated, pointed 
papillae, the direction of tl. 
cending canals is more nearly 
in a straight line. 

The nerve-fibres are thick, 
and form a horizontally 
posed network of ramificati 
from these, separal -tube* 

extend nearly at right ang 
a toward the base of the papilla? 

and, gradually diminishing to delicate filamenl 
finally disappear altogether from view (Fig. 10). 

The thick epithelium is composed of several layers of flat 
cells, with oval nuclei. Those of the deeper or mucous 
present upon their borders delicate dotted markings, an appear- 
ance produced by a row of aculeated projections from the 1; 
margins of the cells; these unite with similar jhbor- 

ing cells, forming a sort of suture (Atlas, Fig. ^ 

There are no glands belonging properly to the gun - 
sometimes acinose glands are found upon the lingual p 
close to its margin. With children the gums frequently ii 
rosette-shaped aggregations of epithelial cells, appearii 
times, to the naked eye like small nodules, which probably are 
merely the remains of the lateral convolutions of the enamel 
germ. 

The Root-Membrane or Periosteum op the B 
delicate connective-tissue membrane containing an abundance 
of vessels and nerves; it is intimately connected with th( 



* Fig. 10 shows three papilla? from the gum of a rabbit, with 
Hum removed, treated with chloride of gold and acetic acid. V 
contains a vascular loop. Bounded and spindle-shaped conm 
cells are scattered throughout the tissue. From the nerve-l 
cylinder, which gradually becomes smaller, is given off at a I 
and extends up to the base of a papilla. Magnified 400 dianu •-. 



ROOT-MEMBRANE — PERIOSTEUM OF THE ROOT. 59 

mucous layer of the gum and with the periosteum of the alveolar 
process, and covers the root of the corresponding tooth. It is 
of unequal thickness, being somewhat thicker near the gum and 
at the apex of the root than in the intermediate portions. In- 
dividuals, too, present varieties in regard to its thickness ; for 
instance, well-preserved grooved teeth have a comparatively 
thicker root-membrane. 

Generally it is of moderate density ; the bundles of connec- 
tive tissue forming it contain no elastic fibres, and inclose fusi- 
form connective-tissue corpuscles; in addition to these, roundish 
elementary organs are met with. According to E. Magitot,* 
the root-membrane consists of two portions : an inner, which 
does not admit of being teased into fibrils; and an outer, lying 
near the alveolar wall, which has the appearance of a fibrous 
structure. The same writer also mentions the occurrence of 
" cellules myeloplaxes," similar to those found in the periosteum 
of bone, and cytoblastions (nuclei invested with a layer of pro- 
toplasm), which occur still more rarely. 

The bloodvessels of the root-membrane originate from, and 
have their exit into, three different localities, viz.: 1, numerous 
tufts of vessels having a longitudinal direction are given off from 
the vessels of the submucous connective tissue of the gums ; 2, 
similar tufts arise from the dental vessels which supply the pulp ; 
3, vessels enter from and empty into the osseous vessels of the 
porous alveolar wall. These relations, which have been men- 
tioned, are much more clearly perceptible in the incisors and 
canines than in the bicuspid and molar teeth, since the root- 
membranes of the latter, in human teeth, but more particularly 
those of the molars of larger mammals, have a less smooth ap- 
pearance, and, where the roots diverge, are thickened. The net- 
work of capillary vessels presents a very uniform arrangement; 
the separate meshes have an elongated form generally; are 
directed towards the surface of the root, and are narrower in 
the vicinity of the neck and apex of the root. 

The inter alveolar vessels, inclosed in a porous, osseous canal, 
pursue a vertical course between two adjacent dental sockets, 

* Memoires sur les Tumeurs du Perioste Dentaire, 1860. 



(JO ANATOMY AND PHYSIOLOGY. 

and are accompanied by the corresponding narrow bundles of 
nerves and loose connective tissue. The distinctness of the 
interalveolar canals varies. For example, the foramina leading 
to the interalveolar canals, which may be seen between the necks 
of the teeth upon the lingual wall of the alveolar process, are 
quite wide in the jaws of young persons, and become obliterated 
with increasing age. The interalveolar vessels divide into 
branches at their exit upon the margins of the alveolar proc< 
and supply the lingual side of the gum.* 

The periosteum of the root is supplied with a rich network 
of nerves. The nerve-tubes are of various diameters, very thick 
and thin ones being united together into bundles. They are 
branches of the dental and gingival nerv D easily be 

demonstrated, and in part also are composed of filaments which 
come through the foramina in the alveolar walls, and from the 
interalveolar canals. 

Development of the Teeth. — In order to render thia -ab- 
ject more clear, I have divided the phenomena, in the order of 
their occurrence, into the following group-. Human embr; 
at so early a period as the second month of pregnari 
rarely available for histogenetic investigation-, as fchej 
generally injured by maceration after the deatli of the ovum 

* The injection of the inferior alveolar arte: ily made by 

forcibly enlarging the posterior portion of the canal of the inferior I 
bone to the depth of a few lines, when the artery may be sought for and at- 
tached to a fine tube corresponding to it in diameter. The mental branch, 
as it emerges from the mental foramen, should either be tied i-r compn 
particularly in larger animals, while the injection is being mal 
count of the anastomoses existing between the periostei 
of the gum, the papillae of the latter also will be tilled. The und 
the calf, roe, dog, or sheep, are well adapted for injection. The delineation 
of the periosteal vessels of the roots of the upper teeth is more mi' 
much as the alveolar artery of the superior maxillary bone supplies only the 
bicuspid and molar teeth, the incisors and canine teeth, on the other hand, 
being supplied by a branch of the infraorbital artery. Injections o( the 
superior alveolar artery will extend to the vessels ot' the posterior port, 
the mucous membrane of the antrum of Highmore and the nasal cavity. 

The capillar}^ vessels of the periosteum of the root poes< — '.:ng to 

the assertions of Ch. Robin, an epithelial covering. I. too, hav 
an appearance somewhat like this upon many of the capillaries, but I 
not convince myself of its constancy. 




DEVELOPMENT OF THE TEETH. 61 

within the uterus. It is, therefore, generally necessary to 
employ the embryos of calves, pigs, sheep, &c. 

1. The first indication of the commencement of the develop- 
ment of the germ is afforded by a 
proliferation of the epithelial struc- 
ture of the mucous membrane cov- 
ering the edges of the maxillary 
arches, in the form of a fold, called (/ 
the dental ridge (Marcusen), which 
is composed of several layers of 
large, flattened, nucleated cells. c 
Corresponding with a superficial, shallow groove, which appears 
upon the ridge, the mucous layer becomes depressed from with- 
out inwards, in the form of a short [on transverse section] cul- 
de-sac, which is tenanted by the cells of the latter layer. This 
tubular depression gradually expands in the form of a pouch, as 
its development progresses interiorly, while, externally, toward 
the outer surface of the mucous layer, it presents a narrowing 
or constriction. This follicle of mucous cells was demonstrated 
by Kolliker to be the enamel germ. These relations are most 
plainly visible in the incisors (Fig. 11). 

Coincident with the depression of the epithelium of the mucous 
layer appears, as has been observed, a shallow groove upon the 
dental ridge, called the dental groove, which is bounded by 
two elevated borders or lips, that upon the facial side being the 
more prominent of the two. 

2. From the floor of the pouch-like expansion of the enamel 
germ, which, upon its periphery, is covered by the cells of the 
mucous layer, and in its central portions is occupied by ex- 
tremely delicate nucleated elementary organs, rises a papilliform 
process of connective substance; this is the primary stage of the 

* Fig. 11. — Primary stage in the development of an incisor of the lower 
jaw ; from the embryo of a calf. Section made perpendicular to the arch of 
the jaw. (a) Dental ridge, consisting of large epithelial cells ; from the 
mucous surface of the epithelium, a follicular process (6), winch already 
presents a constricted neck and is lined throughout with epithelium, extends 
from without inwards, and is the rudiment of the enamel germ ; (c) epi- 
thelium of the margin of the under lip, with rudimentary hair-follicles; 
(d) osseous trabecular covered with periosteum. .Magnified 15 diameters. 



62 ANATOMY AND PHYSIOLOGY. 

dentinal germ, and appears as a single papilla when it represents 
an incisor or canine tooth, and as an elevation with several cusp- 
like processes when it represents the deciduous molars. As the 
neck of the enamel germ becomes more elongated, its Avails be- 
come broken up into folds, which are lined throughout with the 
cells from the mucous layer and give to the neck an appearance 
FlG .. 12 .* like that of a follicular gland with lat- 

. ; . : . r eral offshoots. At a definite distance 
x from the surface of the dentinal germ a 

U| .;' shaded lunated outline becomes visible, 

^j ; which is the primary stage of the i 

sac (Fig. 12). 

3. The development of the enamel 
I| a germ, which becomes -directed towards 
/ the face and undergoes a flexion in its 
constricted portion, n 
\ pletion. As tlie enamel germ inci 

in volume, and the dentinal 
oped from below upwards, more and more into the follicle, the 
former comes to invest the dentinal germ like a cap. A difl 
entiation of the tissue of the enamel germ ensues, whic 
rise to a structure consisting of several layers. \ Ued 

enamelorgan. In consequence of the above-mentioned upward 
development of the conical dentinal germ, and the gradually in- 
creased invagination of the follicle, the peripheral epithelial 
layer of the latter becomes separated into an external and 
internal lamina, the external epithelium (Thiersch) and the 
ternal. The latter is disposed upon the dentinal germ, the 
former upon the roof of the dental sac. Between the I 
thelial laminae lies an intermediate layer. 



Fig. 12 shows the development of an enamel germ, with numerous 
folds, of a lower bicuspid from the embryo of a calf Trarm - 
The mucous layer of epithelium sinks into the mucous membra. 
several secondary donations, and expands in tin, form , 
numerous folds, being snrronnded everywhere by conn* | The 

cells hning the walls of the follicle have a cylindrical form 
of the interior are small and flattened. The rudiment of the dent:,. 
^heated by a shaded outline {b) . Between a and 6 the rudiment 
dentine is elevated into papilliform processes. Magnified B 



DEVELOPMENT OF THE TEETH. 63 

The enamel organ acquires a gelatinous appearance, contains 
no vessels, and becomes thinner as it approaches the base of the 
cap, at the summit of which also it is generally somewhat thinner 
than it is below. The thinnest portion is met with at the base 
of the cap, at the place of reflection, where the 'external and 
internal epithelium are in close proximity. It is composed of 
three principal laminre: (a) the internal epithelial layer, also 
called the layer of enamel cells, which is composed of elongated 
conical cells, with their broad extremities directed toward the 
developing enamel, while, on the other hand, the narrow ex- 
tremities unite with spindle-shaped formative or reparative cells 
(Ersatzzellen), or are inserted between them. The enamel cells, 
as well as their obliquely arranged 
formative cells, inclose a granular 
protoplasm and an oval nucleus. a — 
The formative cells are connected 
by means of a filamentous layer 
with the second principal lamina (/>), 
the spongy tissue. This forms the _ 
principal mass of the enamel organ, 
and its transparent basis-substance 
is occupied by cells with stelliform 
radiating processes. The bodies of 
the cells inclose an oval nucleus; 
the processes unite to form a net- d ~ 
work, the meshes of which become 

e 

more narrow from within outwards, 
and are in relation with an inter- 

* Fig. 13. — Transverse section of the enamel organ of an incisor from a 
human foetus, the section taken from the vicinity of the reflection of the cap, 
whore the organ has already become quite thin. (a) Enamel cells (ex- 
ternal [?] epithelium), with the gradually more obliquely disposed formative 
cells (Ersatzzellen), which ultimately assume a horizontal direction, and 
become spindle-shaped ; (b) multi radiating flattened cells, which form a net- 
work by means of their connecting processes, and belong to the Bpongy 
layer ; (<•) layer of spindle-shaped cells, with oblong nuclei, analogous to 
those adjoining the layer of enamel cells; (<7) groups of cells belonging to 
the external epithelium, and lying in sac-like cavities; between the groups 
are the openings of capillary bloodvessels. The papilhe of the dental sac, on 
account of their oblique position, are represented obliquely within the sec- 
tions ; (c) lax connective tissue of the dental sac. Magnified 400 diameters. 




64 



ANATOMY AND PHYSIOLOGY. 



Fig. 14. 



mediate layer composed of horizontally disposed spindle-shaped 
cells. Outside of the latter appears (c) 
a group of cells, called the external epi- 
thelium, which invest the papillae pro- 
jecting into the enamel organ from the 
wall of the dental sac (Fig. IS 

The dental sac, from the floor of which 
proceeds the dentinal germ, is developed 
opposite the surface of the latter, and in- 
vests it and the enamel germ, forming a 
connective tissue envelope around the 
two, the continuity of which ifl broken 
only at that part which n de- 

scribed as the constricted portion or neck of the enamel g 
and is connected with the mucous layer of the epithelium. It 




* Yig. 14.— Injected bloodvessels from the dental sac of a new-born cl 

The larger ones lying outside form a network, with 8 
teriorly, delicate capillaries are given off and form unh- 
and there, directed toward the enamel organ. Magnified 80 diamel 

f The spongy tissue was formerly considered to 
tissue, until Huxley and Kolliker demonstrated that it is 1 with 

the epithelial structures. Opinions are still divi-1 r > n 

which the enamel is developed out of the enamel ells. I 
I also uphold, maintains that it is by the direct calcification of the enamel 
cells, and Waldeyer (S. Strieker's Handbuch der Gewebelehre) ad 
strong evidence in support of this view, the occurrence of enamel 
fragments of enamel prisms in intimate connection, the latter r 

adherent to the former in the form of proa , A.C rdii g I 

rifaction (petrifiziren) of the enamel cells commences in the 
while the axial portion of the protoplasm retains itfi 
in isolated cells forms a kind of process (Tor 

Cells). The other view, which Kolliker formerly held, is based upon 
idea, that the enamel is a cuticular structure. Guillot. B 
as the result of their investigations with reference to this 
the teeth and their appendages are developed in the submucous t - 
entirely free and independent of all other tissues. Max Reicherl 
inclined to this erroneous view (Dubois-Reichert's Archiv. 1- ding 

to whom, the enamel organ originates from the coriom, and not from the 
epithelium of the mucous membrane of the mouth. The gelatit. 
together with the stellate cells of the enamel organ, hi ls connec- 

tive tissue. Kollmann has recently published a work, agreeii . 
ally with Kollikers theories (Entwicklung der Milch- and Ers 
Zeitschr. f. wiss. Zoologie, Bd. 20). 



DEVELOPMENT OF THE TEETH. 65 

is closed, at a quite early period, in the manner already de- 
scribed, before there is the least trace of the tooth cap. It be- 
comes richly supplied with bloodvessels and nerves. That por- 
tion of the sac, particularly, which invests the enamel organ, 
becomes elevated into rows of papillary excrescences which are 
covered by the cells of the external epithelium of the developing 
enamel organ. The wall of the sac is divided into a compact pe- 
ripheral or outer, and an inner lamina of a more lax tissue. It is 
traversed by numerous interlacing bundles of nerves, and the 
bloodvessels also are very abundant ; the larger of these are 
distributed in the outer, and the smaller in the inner lamina. 
As they pursue a generally straight course, they give rise to 
oblong meshes (Fig. 14). In that lamina of the dental sac 
which is in relation with the enamel organ, capillaries extend 
into the corresponding papillae, where they form anastomotic 
loops. These vascularized papillae are so 
intimately united with the enamel organ, 
that, together with the anastomotic loops, 
they remain adherent to the enamel organ 
after the dental sac has been detached 
(Fig- 15). 

The dentinal germ receives bloodvessels 
and nerves from that portion of the dental 
sac with which it is in contact, and becomes 
developed into one or several papillae or 
prominences, according to the number of 

tubercles which the crown is to present. Consequently the 
rudiments of canine teeth present one, and those of molar and 
bicuspid teeth several papillae. Well-developed dentinal cells 
with their processes, such as have been described in connection 
with the pulp, are observed at a comparatively early period. 
Large vascular twigs extend up and down from the base of the 
germ, and ramify in various directions towards its surface, where 



* FrG. 15. — Injected capillaries which remained adherent to the enamel 
organ of a bicuspid tooth, from a calf, the dental sac having been detached. 
The anastomotic loops have been torn from their connection with the vessels 
of the dental sac, and reach almost to the layer of enamel cells. Magnified 
30 diameters. 

5 




6Q 



ANATOMY AND PHYSIOLOGY. 



Fig. 16.* 




they terminate in loops. The latter pursue a straight course in 
young germs (Fig. 16). The connective tissue of the germ is 
very soft, contains numerous cells, and be- 
comes exceedingly cloudy on the addition 
of acetic acid. The dentinal cap, which 
primarily is exceedingly thin, is blended 
with the enamel cap, while, from the be- 
ginning, the enamel and dentine are devel- 
oped in opposite directions. The dentine 
is formed by the deposition of new layers 
from without inwards, while the enamel, as 
above demonstrated, is developed in a 
similar manner from within outwards. 
The enamel germ of a permanent tooth, 
which has a single root, is developed, at an early period, upon 
the lingual side of the milk teeth, in 
the form of a cul-de-sac. It commences 
in the form of a direct depression 
of the mucous layer of the epithelium 
from the dental groove, between the 
facial and lingual lips of the dental 
ridge, and has a common origin with 
the enamel germ of the milk tooth (Fig. 
17). The follicle presents lateral folds, 
which not unfrequently occur in large 
numbers. The closed terminal portion 
of the follicle was recognized by Kol- 
liker as the enamel germ of the perma- 
nent tooth. The connecting branch of 
the follicle, which extends outwardly 
towards the face, is in direct communi- 
cation with the external epithelium of 
the enamel organ of the deciduous tooth. 



Fig. 17.f 




* Fig. 16. — Injected terminal loops from the pulp of a permanent ineisor 
of a new-born child. The vessels pursue a straight course. The loops are 
partly single and partly complex. Magnified 30 diameters. 

f Fig. 17 shows a follicle of mucous cells extending from the dental rids:e 
to the enamel germs of the milk and permanent teeth ; from a human embryo 
of three months' growth. The cells of the mucous layer of epithelium dip 



DEVELOPMENT OF THE TEETH. 



67 



The connection of the outer with the inner epithelium, as well 
as a general view of the developing crown, the tooth cap, and 
the dental sac, together with the parts in the immediate vicinity, 
may be observed in sections of the jaws of embryos of a suitable 
age, which have been decalcified by means of diluted hydro- 
chloric and chromic acids. The inner epithelium commences at 
the base of the dentinal germ (Fig. 18), and extends along the 

Fig. 18.* 




down into the substance from the dental groove (a) of an incisor of the lower 
jaw, and resemble, somewhat, a tubular gland with lateral offshoots. At 
about the middle of the follicle, which is lined throughout with cylindrical 
cells, it is connected by a transverse process (b) with the external epithelium 
of the enamel organ, the spongy layer of which is represented (c). The 
inferior closed portion of the follicle is the enamel germ of the permanent 
incisor tooth. Magnified 80 diameters. 

* Fig. 18. — Sagittal .-ection of a lower jaw from the embryo of a dog, 
showing an incisor within its dental sac. (a) Facial lip of the dental ridge; 
(b) epithelium ; (c) corium, with papillae in the dental ridge, and cavities of 
transversely divided vessels; (d) enamel germ of the permanent incisor 
containing an aggregation of epithelial cells ; its connection with the enamel 



68 ANATOMY AND PHYSIOLOGY. 

entire outer surface of the dental cap. The thickness of the 
pulp bears a direct relation to that of the cap ; that is to say, 
the thicker the former, the thinner the latter ; and the pulp 
rests upon the floor of the dental sac. The latter has a rounded 
form, corresponding with the developing dental .crown, lies be- 
neath the facial lip of the dental ridge, within the maxillary 
groove, and is intimately connected with the exceedingly vascu- 
lar and nervous submucous connective tissue of the gum. and 
Avith the layer of connective tissue which lines the maxillary 
groove.* 

organ of the deciduous tooth does not appear in the section ; (e) anterior, (e') 
posterior, osseous lamella of the jaw with rounded summits; (f) completed 
enamel of the dental cap ; in the section it is separated, somewhat, from the 
(g) layer of enamel cells; (A) retiform connective tissue of the dental sac ; 
(i) outer epithelium of the enamel organ completely investing the papilla 
of the dental sac; (k) spongy layer of the enamel organ; (I) completed 
dentine of the cap; [m) layer of dentinal cells ; («) dental pulp with wide 
vessels in its interior. Magnified '20 diameters. 

* The mode of development of the dentine is so far determined that we 
know positively that the dentine is developed from the dentinal cells. We 
may also readily demonstrate that, as soon as the connection of the dentinal 
with their formative cells occurs, the calcification of the contents of the 
dentinal cells begins ; that their principal and accessory processes remain 
attached and are transformed into dentinal fibres, and that a constant depo- 
sition of calcareous salts into the cells takes place from the blood. 

By the continuous transformation of formative cells into dentinal cells, 
the process goes on, and new layers of dentine are deposited constantly by 
progressive calcification. Kolliker (op. cit.) maintains another view, a 
modification of the last, namely, that the calcified substance, which is found 
between the dentinal fibrils (basis-substance, or matrix, of the dentine 
be considered an excretion from the dentinal cells, and consequently is not a 
product of the immediate calcification of the latter. 

Another question arises, viz., how do the globular masses originate, and 
what relation do they bear to the normal development of the dentine ? The 
globular masses found on the inner surface of the dentine of the teeth of 
children are permeated by dentinal canals, and in accordance with the first 
theory may be considered to be the result of a coalescence of separate groups 
of calcified dentinal cells. There are two possibilities, in regard to the 
globular masses which are intercalated between the systems of dentinal 
canals, without being pierced by them, namely: that in these localities the 
processes within the groups of calcified cells were prematurely destroyed, or 
that, in consequence of an arrest of development, the process of calcification 
of the dentinal cells progressed merely to the formation of globules of cal- 
careous salts. 



DEVELOPMENT OF THE TEETH. 69 

4. The dental cap, considered as the aggregate of calcified 
dentinal and enamel cells, maintains during its development the 
shape given to it by the arrangement of the cells ; it increases 
in thickness, and eventually becomes the crown of the tooth ; 
contemporaneous with the growth of the latter the enamel organ 
gradually becomes thinner, and finally shrivels up completely. 
When the development of the crown is accomplished, that is, 
when no new layers of enamel are formed, the growth of the 
radical portion of the tooth, from the edge of the crown, com- 
mences ; the dentinal cells adopt a more horizontal position, 
and consequently the dentinal canals also assume a more hori- 
zontal direction. At the margin of the crown the dental sac 
contracts, and upon its inner surface the formation of the cement 
is effected, increasing gradually as the formation of the root 
advances ; the lower segment of the dental sac becomes, there- 
fore, the root-membrane of the tooth. 

Contemporaneous with the latter processes occurs the formation 
of Nasmytlis enamel membrane, which is interpreted in various 
ways. This membrane, called by Kolliker the cuticle of the 
enamel, is considered by him to originate in this manner, viz.: 
that an additional coherent layer (cuticle) is secreted by the 
enamel cells, after the completion of the formation of the enamel, 
to serve as a protection for the whole. Waldeyer regards it as 
the product of the cornification (Verhornung) of cells. J. Tomes 
holds the opinion, that the membrane belongs to the cement, 
because it is continuous from the crown upon the cement, as 
may be demonstrated on teeth which have been treated with 
dilute hydrochloric acid ; moreover, the membrane is thickened 
in the depressions upon the crowns of the molars, and in these 
localities distinct bone-corpuscles likewise occur. These argu- 
ments, together with data furnished by comparative and patho- 
logical anatomy, uphold the latter view, in my opinion. In the 
development of teeth with irregularities in the enamel, the adap- 
tations of the dental sac and the enamal organ to depressions in 
the crowns may easily be demonstrated, and there remains, 
finally, an outer covering of cement upon the masticating sur- 
faces of the crowns. The case illustrated in the Atlas, Fig. 9, 
where the radical cement passes without interruption into a 



70 



ANATOMY AND PHYSIOLOGY. 



Fig. 19. : 



well-marked coronal cement, which covers the entire masticating 
surface and insinuates itself between the folds of enamel, is ex- 
plained by the latter theory. 

5. The growth of the pulp root and the contiguous zones of 
the dentine keeps pace with the formation of the cement which 
takes place externally to the latter. While the growth of the 
dentine in thickness gradually diminishes, that of the cement 
increases. As the peripheral portions of the dentine are always 
formed first, it will readily be understood why an incomplete 
root presents at its extremity a sharp margin and a dome-shaped 
cavity, called by the dentists an unclosed root. The formation 
of the root is completed when its canal no longer presents a 
funnel-shaped expansion at its extremity. 

6. The development of the osseous walls of the teeth is first 
indicated by an osseous dental groove, which is more 
distinctly marked upon the lower jaw, and is inclosed 
by a facial and lingual lip. It is shallow and flattened 
posteriorly (Fig. 19). As this groove becomes deeper 

and wider, lamellar projections appear upon its interior 
wall, the first making its appearance between the two dental 
sacs of the incisors. At about the same time, flattened spinous 
processes also appear toward the upper margins of both the 
labial and lingual walls (Fig 20 a). These processes grow 
towards one another and gradually complete the continuity of 

the wall. In this way an osse- 
ous case, of a fine spongy tex- 
ture, is formed around the den- 
tal sac, which gradually con- 
tracts,but remains permanently 
open externally. It may be 
demonstrated separately, and 
is called the bony socket, or 
alveolus of the dental crown. 
The size, position, and re- 



FlG. 20. a, b.f 




* Fig. 19.— Lower jaw of a human foetus, at the commencement of the 
third month of pregnancy, seen from above, in order to give a view of the 
groove in the bone, which becomes flattened from before backwards. The 
coronoid processes and condyles are already indicated. Natural size. 

f Fig. 20, a.— Macerated left half cf the inferior maxillary arch, from a 



DEVELOPMENT OF THE TEETH. 71 

spective distances of the sockets from each other can be demon- 
strated to the best advantage in sections of decalcified jaws, 
corresponding with their curves. All the cells are equidistant 
from the edge of the gum, while their distance from the inferior 
margin of the lower jaw decreases from before backwards, that 
is, the socket of the middle incisor is most distant, and that of 
the second molar is nearest, which relation corresponds with the 
growth of the bone in depth from before backwards (Fig. 20 b). 
When the growth of the root commences, and the corresponding 
segment of the dental sac becomes the root-membrane from 
which the cement originates, a partial process of resorption 
takes place in the osseous coronal sockets. This is but a tem- 
porary process, and continues only so long as the crown is in 
an embryonic condition. As far as I know, Tomes was the first 
to call attention to the important circumstance, to be considered 
later, namely, the fact that resorption of a portion of the walls 
of the alveoli ensues in order to prepare the way for the passage 
of the teeth through the gum. 

7. The formation of the twenty osseous alveoli of the crowns 
is nearly completed in the eighth month of pregnancy, only the 
facial walls of the alveoli of the canine teeth, and the posterior 
wall of the second deciduous molar, particularly in the upper 
jaw, remaining, for the most part, membranous. Consequently 
the osseous septum between the second deciduous and first per- 
manent molar is wanting. Since the posterior are considerably 
wider than the anterior alveoli, it will be seen that the facial 
lamina of the alveolar process of the upper jaw describes a wide 

foetus, at the seventh month of pregnancy. View from the lingual side. 
The partitions or septa for the incisors are partially formed ; the facial wall 
of the canine tooth still presents a gap. The septa for the milk molars are 
indicated bj' slight ridges; that for the first permanent molar is already per- 
ceptible towards the coronoid process. Natural size. 

Fig. 20, b. — Left half of the inferior maxillary arch, from a new-born 
child; decalcified by means of dilute hydrochloric acid, and bisected by an 
incision corresponding with its curve. The incised surface of the outer half 
is exposed to view ; the dental sac and contents are removed. The separate 
walls for the dental sacs of the milk teeth are completely developed ; the 
septum for the first permanent molar is seen to be partially developed within 
the coronoid process. Natural size. 



72 ANATOMY AND PHYSIOLOGY. 

and semicircular curve, internal to which lies the narrower semi- 
elliptical bow of the lingual lamina. In the lower jaw the 
lamina of the alveolar process extend nearly parallel to each 
other, from before backwards; the anterior segments extend 
from the median line outwards ; behind the alveoli of the canine 
teeth they bend abruptly backwards, and thus describe cm 
similar to the letter S; the posterior extremities of the two 
rami of the lower jaw consequently present a greater divergence 
than those of the upper. 

If the inferior maxillary arch be examined from below st this 
same period of development (the eighth month), in itfl relation 
to the superior arch, both jaws being left in their natural p 
tion so that the suture of the palatal processes and the Bjmpl 
of the lower jaw lie in the same perpendicular plane, the _ 
divergence of the posterior segments of the inferior arch will 
perceptible. A profile view presents a notable projection of the 
upper beyond the lower jaw, an appearance occasioned in | 
by the fact that the mental process is not yet devel< 

The alveoli for the crowns of the incisors are bi Q the 

facial than on the lingual side. While they expand, with the 
growth of the crown, their orifices upon the alveolar ridge 
contracted, because the facial and lingual walls, as they 
veloped from below upward, incline toward each other. The 
alveoli of the canine teeth are characterized externally I 
prominent ridge, the canine eminence, and generally bnlg 
than the other sockets. Their facial walls in the upper jaw 
almost entirely ossified at the commencement of tin 
month after birth. The openings leading to the oblong al ■ 
of the milk molars, particularly that of the second molar, are 
wide at first, but later contract gradually. In the first months 
after birth, the facial and lingual walls, together with tl 
between the alveoli, are developed from below upward, and in- 
cline toward each other. The margins of each of the 
in the course of their development, present a concavity, at first 
usually slight, but still perceptible, which is the result of c 
mencing resorption. These taken together give rise to the 
festooned appearance of the edges of the alveolar borders. The 




FIRST DENTITION. 73 

latter conformation is exhibited first of all and most distinctly 
by the alveoli of the incisors. 

First Dentition. — The growth of the root in length keeps 
pace with the process of resorption at the alveolar borders. The 
crown presses against its membranous covering, and becomes 
perceptible to the touch externally, as the so-called tooth prom- 
inence (Zahnpille). In consequence of the continuous pressure 
of the crown upon the vessels and nerves of the summit of the 
dental sac, the latter undergoes complete atrophy ; the inter- 
lacing bundles of connective tissue 
acquire a dried and tense appear- 
ance and a yellowish color. That 
part of the gum which is in im- 
mediate relation with the dental 
sac undergoes a similar process, its 
numerous vessels being subjected 
to extreme tension (Fig. 21). The 
membranous coverings gradually 
become thinner, and at last trans- 
parent, when the edge of an incisor, or the tubercles or cusps of 
the canine and molar teeth, are exposed to view. On account 
of the constant onward pressure of the crown, which is com- 
mensurate with the advancing growth of the root, the gum neces- 
sarily recedes and, after the eruption of the crown is completed, 
attaches itself to the neck of the tooth, by which means its sub- 
mucous layer maintains its connection with the dental sac, which 
latter becomes the root-membrane. 

The preparation for the eruption of the central incisors is 
manifested by the above-mentioned process of resorption, which 
gradually becomes more evident, upon the lingual and facial 
walls of their alveoli, by an increase in the concavity of their 
margins. Recently cut incisive edges of the central and lateral 
deciduous incisors present two shallow indentations. The re- 
sorption upon the alveolar margins of the lower incisors is much 

* Fig. 21. — Injected gingival bloodvessels of the prominence (Zahnpille) 
over the molar of a new-born sheep. View from above. The vessels con- 
verge toward the summit, where a capillary network is presented. Magni- 
fied 5 diameters. 



74 ANATOMY AND PHYSIOLOGY. 

more evident at first than it is on those of the upper. The re- 
sorption of the latter, however, soon follows, and commonly is 
more conspicuous on the facial than on the lingual walls of milk 
teeth. 

The central incisors advance perpendicularly, while the lateral 
incisors present a lateral inclination of the facial coronal sur- 
faces, which is more decided when still inclosed within their 
bony capsules than is the case after their eruption ; they mi 
therefore, during the latter process, be twisted considerably 
toward the median line of the jaw. 

The first milk molars generally are cut in the first months of 
the second year, and not unfrequently earlier in the upper than 
in the lower jaw. When the masticating surfaces of these teeth 
have already advanced to their proper level in' the dental range, 
their roots are barely half formed, and the extremities of the 
latter present a wide cavity and a sharp edge. While the 
canine teeth are still deeply imbedded in the jaw, within their 
alveoli, they present the most notable inclination of all the 
teeth, their crowns being inclined toward the median line of the 
jaw, and their necks laterally. As they approach the summit 
of the alveolar ridge, they experience a slight lateral inclinat 
in order that they may advance in the space between the lateral 
incisors and first molars. Another peculiarity of the canines 
afforded by the fact that they lie farthest from the alveolar 
ridge and consequently are obliged to traverse the 
distance in order to reach it. There is, however. cir- 

cumstance which is very much in their favor, namely, that the 
resorption upon their alveolar margins extends higher in the 
upper, and deeper in the under jaws than is the case with the 
remaining teeth. When their eruption has pi far 

that the coronal extremities have reached the level 
the adjacent teeth, the roots have barely attained half their 
final length. 

The second upper molars not unfrequently make their appear- 
ance before the corresponding lower teeth. With these, the 
first set of teeth, the milk or deciduous set is completed, gener- 
ally by the end of the second, or occasionally not antil the 
end of the third year. 



FIRST DENTITION. 75 

When the crowns of all the milk teeth have attained their 
full growth and proper relations, the growth of the roots is 
still more or less incomplete, in proportion to the early or late 
eruption of their respective crowns. Even the extremities of 
the roots of the central incisors are scarcely closed at this 
period. 

The periods at which the eruption of the milk teeth com- 
mences and terminates vary considerably. While, in rare cases, 
children enter the world with their lower central incisors already 
cut, sometimes the latter do not make their appearance until 
the end of the first year after birth. As has been observed 
before, the eruption is completed generally at the end of the 
second year after birth, though, frequently, it is prolonged 
many months beyond this period.* 

It would be an interesting point to determine the normal in- 
tervals between the eruption of the different kinds of teeth, 
since, from the longer or shorter intervals, an approximate con- 
clusion might be deduced concerning the growth of the jaw in 
its different dimensions; variations, however, in this respect are 
presented in the same individual. In general, it may be said 
that the interval between the completed eruption of the central 
and the lateral incisors, and between that of the latter and the 
first molars, is about ten or twelve weeks for each kind men- 
tioned, while that between the eruption of the first molars and 
canine teeth is prolonged to twenty or twenty-four weeks ; the 
second molars succeed the canine teeth after a similar period. 
The intervals before the appearance of the canine teeth and 
second molars, therefore, are about twice as long as those be- 
tween the first mentioned kinds of teeth. 

In regard to the eruption of the teeth in the upper and lower 
jaw respectively, it is the rule that the lower incisors appear 

* The eruption of the deciduous teeth usually takes place at about the 
following ages: 

Central incisors, 7th month. 

Lateral incisors, ..... 9th " 

First molars, 12th " 

Canines, 18th " 

Second molars, . . 24th " 

T. B. H. 



76 ANATOMY AND PHYSIOLOGY. 

first, and generally the upper ones succeed them in a very short 
time. The reverse is the case, frequently, with the mob; 

Second Dentition. — The eruption of the first molars ushers 
in the shedding of the teeth. They appear in the seventh year 
and generally in the upper jaw earlier than in the lower. 
Toward the end of the second year, the crowns of those in the 
upper jaw are situated high up in the maxillary tuberosity, and 
those in the lower jaw, in the coronoid process, and as the de- 
velopment of the jaws progresses, they descend towards the 
dental range. ' The alveoli of the crowns undergo a pi 
gradual resorption in the vicinity of the summits of the latter, 
and contemporaneously with this process, the growth of the 

radical portion 001 



Fig. 22.* 



some time before the e 
of the first molars, t! 
of their alveoli have und< 
a considerable amount of re- 
f.^ sorption, but are still separated 

HBk^ from the alveoli of ti 
wMmR molars by partially mem 1 
^fttihr ous septa (Fi-. l'J . C.ni-ur- 
5 rent with the emergence of the 

teeth, the alveoli for the roots 
in the upper jaw form three broad, cup-like dep 
rated from one another by projecting partition-walla 
In the lower jaw are found two similar shallow, flattened de- 
pressions. Generally, at this period of their d- t, the 
roots present remarkably sharp edges and br 




* Fig. 22.— Eight half of the upper jaw of a child 
years of age. View of the palatal surface. The pi 
seen to have made considerable progress upon the margins of the i 
alveolus of the first permanent molar (near a), and the Latter commm 
with the coronal alveolus of the second permanent molar. TI 
pressions at the bottom of the cavity correspond with the three incur, 
formed roots belonging to the detached tooth; b) incisi 
is met with, sometimes, in adults. Upon the lingual wall of 1 
process, and corresponding to the localities of the lateral 
molar of the milk set, openings are visible for the corresponding permanent 
teeth, produced by the process of resorption. Natural siae 



SECOND DENTITION. 77 

When the coronal cusps of the first molars have reached the 
level of those of the deciduous molars, their roots are scarcely 
more than a few millimetres in length. The subsequent growth 
of the roots in length and of the jaws in depth is a compara- 
tively rapid process. 

The shedding of the teeth involves all the milk teeth, and 
commences as soon as the crowns of the permanent teeth, 
through reason of the development of their roots, draw near to 
the alveoli of the milk teeth. A series of phenomena then en- 
sues in the alveoli, and in the milk teeth themselves, which have 
been embraced under the general term resorption. This process 
manifests itself by a loss of substance which commences in the 
alveoli of the milk teeth, then usually attacks the apices of their 
roots, and finally the entire roots and, in many case^, involves 
a large portion of the crowns. Generally this process attacks 
the milk tooth upon the side towards the advancing crown of the 
permanent tooth, though frequently it commences at many 
points simultaneously, and gives rise to pitted or funnel-shaped 
depressions, grooves, or irregular facets, looking like the effects 
of corrosion, all of which are characterized by their rough, ex- 
posed surfaces and sharp edges. We are indebted to Tomes for 
the first thorough histological investigation and correct inter- 
pretation of the various phenomena presented by this process of 
resorption. 

If we examine closely a portion of the cement of the root of 
a deciduous tooth which has been affected by this process, we find 
what at first appears to be a simple depression; under the micro- 
scope, however, this is found to be made up of a number of smaller, 
cup-shaped excavations, which, seen from above, are bounded by 
sharp, elevated laminae and, upon still closer examination, dis- 
play, in suitable places, a network of projections in each micro- 
scopic cavity. The bone-corpuscles, together with the interme- 
diate substance, undergo a decomposition : first of all, a molec- 
ular cloudiness occurs in their immediate vicinity, and also in 
the intercorpuscular substance ; the radiating bone-canaliculi 
become indistinct, disappear, and the bone-corpuscles, deprived 
of their radiating canaliculi, are isolated within the cavities 
which become more clear by the solution of the substance con- 



78 ANATOMY AND PHYSIOLOGY. 

tained in them, and in which the network of delicate projecting 
laminae gradually disappears ; the walls of contiguous cavities 
become thinner, and finally are entirely absorbed (Atlas, Fig. 
112). As the same process is repeated, and gives rise to larger 
and smaller groups of such indentations (Resorptionsalveolen), 
the cement substance in the affected localities is entirely de- 
stroyed, so that, finally, cross-sections present an excavation with 
an irregularly notched boundary. 

The same process also takes place in the dentine when simi- 
lar indentations are produced by resorption and occasion a 
roughness of the surface. Not merely those portions adjacent 
to the cement are attacked by this process, but the inner por- 
tions also, which inclose the root canal (Atlas, Fig. 111). 

Resorption of the milk tooth is frequently accompanied by a 
new formation of osseous substance, a phenomenon of frequent 
occurrence with new formations, that is to say, involution by 
the side of evolution. 

The new formation and resorption can readily be studied in 
that portion of the cement where no rows, or, still better, where 
a single row of bone-corpuscles occurs. In addition to the in- 
dentations produced by resorption already described, which quite 
frequently are coated with the remains of the organ: 
substance, cross-sections also present clear, hemispherical, 
sharply defined masses imbedded in the cement ; these are 
either separate or grouped together, and gradually extend be- 
yond the boundary of the cement even into the dentine, and not 
unfrequently assume a radiating arrangement. 

The central portion of these masses contains irregular cavities. 
which denote the points where the process of resorption com- 
menced. The osseous substance, which encroaches consider;: 
upon the dentine, is always sharply defined ; the corpuscles, 1 
wise, either singly or in groups, are inclosed bv a bright cap- 
sular layer (Atlas, Fig. 110). Such corpuscles resemble voi; 
immature bone-corpuscles, the canaliculi of which have not 
formed their mutual connections. Not unfrequentlv the cor- 
puscles are irregularly formed, elongated : present several 1 
offshoots, or are large, without any definite form, as if result 
from a blending together of separate ones. As they increase in 



SECOND DENTITION. 79 

volume, and lose their proper characteristics, they assume an 
appearance like that of gaps, resulting from interstitial resorp- 
tion, and filled with amorphous calcareous salts, and all the more 
so from the fact that very decided evidences of resorption are 
found in their vicinity. 

The newly-formed osseous substance is immediately subjected 
to a peripheral resorption, while the capsule of the corpuscles 
thickens, and the latter, finally, are destroyed. The cloudy, 
granular, discolored substance contains a greater or less amount 
of fat, which is the remains of the disintegrated tissue. 

When the resorption of the milk teeth has progressed so far 
that a small portion only of the crown remains, the enamel, 
likewise, becomes eroded 
and resorption indenta- f ^^ M ^^^^ * ' 



tions make their appear- 
ance in it also (Fig. 23). I V 7 ^ 
Tomes has also observed MJB '*P*lp8 
the development of osse- 
ous substance upon the 
outside of the enamel. 

If a milk tooth, in 
which resorption has made 
some progress, be sepa- 
rated from the jaw, a loose, spongy substance remains adherent 
to it, which a long time ago, was claimed by Laforgue and 
Bourdet to be the absorbent organs. It was supposed that the 
latter secreted a fluid capable of dissolving the substances of 
the tooth. Tomes made a microscopic examination of this pa- 
pillary organ, and states that its surface is made up of peculiar 
multiform cells, each one being composed of several smaller 
cells, the number varying from two or three to as many as four- 
teen or fifteen. Some few deviating forms bear a strong re- 
semblance to the cells, described by Kblliker as myeloid cells. 



* Fig. 23. — Resorption indentations which penetrate from the surface of 
the enamel toward the deeper layers, resembling, in the manner in which 
they are grouped together, glandular lobes, and filled with a cloudy, gran- 
ular mass. The contiguous portion of the enamel is in its normal condition. 
Magnified 250 diameters. 




80 ANATOMY AND PHYSIOLOGY. 

Each hemispherical depression of the absorbent surface of the 
tooth is occupied by such a cell as has been described. Beneath 
the surface of the papillae, there are commonly found nucleated 
cells and free nuclei, and, in the deepest layers, a fibrous tissue 
in the process of development. 

According to my experience upon this point, which indeed is 
limited, these compound cells (Tomes) are not of constant occur- 
rence; I have not been able to discover them in some ca.v 
have perceived merely aggregations of single cells of connective 
tissue. Hohl has succeeded only in one case in discovering a 
few gigantic cells, and he is of the opinion that the large cells 
described by Tomes are nothing but nests of cells with connective- 
tissue capsules. How the destruction of the hard Babstan< 
the tooth is accomplished by these cells, we have no clear con- 
ception ; to me it seems more probable that a fluid is secreted 
by the cells, which dissolves the hard substance, than the t! 
held by some, that these cells are of a parasitic nature, that is 
to say, that the dental substances are eaten up. as it v, 
the cells absorb the latter. Possibly amoeboid movements mav 
be the occasion of the wasting of the tissues. 

The so-called absorbent organ, however, indue- 
seous formation, already described, since the cement, notwith- 
standing its partial resorption, evinces, on the other hand, a pro- 
ductive activity which results in the development i 
stance within the dentine and upon the exterior of the en 
When the cells of the milk teeth are absorbed, those of the per- 
manent teeth are completed.* 



* The organ of resorption probably is developed from the con, 
of the root-membrane of the milk tooth, and from the medullar 
the adjacent osseous tissue, and is, essentially, a granulation tissue, similar 
to that which we find in many inflammatory affections of tin 
tumors which are developed in the osseous substance. W« 
one band, upon the periphery of sarcoma, cam . 
contiguous hone, and on the other hand, frequentlv a growth of tral 
osseous tissue. Therefore, during the shedding of the teeth, an hvp 
condition occurs in the root-membrane and the medullary mal 
bone adjacent to it; the activity of the cells becomes augmented, in 
quence of which the whole process of nutrition is carried on m 
than under ordinary conditions ; the young, more vigor* pplant 

the older, enfeebled ones. In the organism of youth, also, we find that in the 



SECOND DENTITION. 



81 



"When the resorption of the milk tooth is completed with the 
exception of a certain portion, variable according to local cir- 
cumstances, its alveolus has, for the most part, disappeared, and 
that of the permanent tooth occupies its place. This, however, 
is not always the case, particularly when the milk teeth are shed 
prematurely, or the permanent teeth occupy anomalous posi- 
tions, and in such cases there remains upon the summit of the 
alveolar process an oval or circular channel, in the centre of 
which is found a conical osseous papilla, which is to be consid- 
ered as the remains of the bony substance which, in its growth, 
occupied the pulp-cavity (Atlas, Fig. 3). 



Tiu. 24.* 




growth of bone, there occurs upon one side resorption, and upon the other 
production, us for example, in the flat bones of the skull, resorption occurs 
on the inner surface, growth on the outer surface which is in relation with 
the galea aponeurotic^. Again, in the tibia, resorption takes place in the 
central medullary canal, and growth upon the periosteum and epiphyses. 
These processes, too, explain the increase in size of the cranial cavity and 
central medullary canal of the tibia. 

* Fig. 24. — Set of milk teeth with the corresponding permanent teeth 
still imbedded within the jaw. The first permanent molars (a) have already 
emerged from the jaw both above and below, so that the second dentition 
has commenced. Profile view from the right side. The somewhat inclined 
crowns of both permanent incisors are visible behind the extremities of the 
roots of the milk incisors. The crown of the upper canine tooth (6) presents 

6 



Fig. 25.' 




g2 ANATOMY AND PHYSIOLOGY. 

Before passing to the consideration of the separate teeth, it is 

to be premised that the permanent 
teeth in the upper jaw are arrai 
somewhat differently from those in 
the under jaw, in their relations to 
the milk teeth, and also that the dif- 
ferent kinds of teeth present varia- 
tions in this respect (I 

Commonly, toward the end of 
the fourth year, small, barely per- 
ceptible apertures appear in the under jaw, behind the cenl 
milk incisors, and adjacent to the lingual alveolar margin ; these 
gradually enlarge so as to admit the incisive edges of the per- 
manent central incisors between their smooth borders. In the 
meantime, similar apertures become visible behind the lateral 
incisors. When the edges of the permanent central incit 
have reached the level of the lingual alveolar margin, tl 
of the lateral incisors are still some millim- and are 

inclined somewhat toward the medium line and backwai 
25). Since the total breadth of the crowns of the ma- 

nent incisors is greater than that of the corresponding milk 

a marked inclination, and is situated high up in its alveolus; the 

manent canine (c) likewise occupies a deep portion. Th 

manent bicuspids are grasped by the diverging roots of the milk m< 

The mental foramen [d) is seen between the first and second milk U 

The crowns of the second permanent molars, inclosed within their al\ 

are imbedded in the maxillary tuberosity and coronoid pr 

size. 

* Fig. 25. — Front view of the lower jaw at the comm< "f the 

process of shedding the teeth, showing the relativ* 
milk and permanent teeth. On the left side, the two milk in 
canine were left in their natural positions, with reference to the permanent 
teeth lying posteriorly and interiorly. The process : ;her 

advanced in the extremity of the root of the central incisor, than it 
that of the lateral. On the right side, the milk teeth have I 
the permanent teeth lie within their alveoli in an inclined pli 
notched edges of the permanent central incisors have reached t' 1 
margin, those of the laterals being situated about two millimetre* 
down ; the latter teeth, also, are inclined somewhat toward the median line, 
although to a less degree than the conical crowns which are dee| 
and inclosed within their alveoli. Natural size. 







SECOND DENTITION. 83 

teeth, the eruption of the former, side by side, would be impos- 
sible, so long indeed as the milk canine teeth remained in situ, 
if provision were not made to secure sufficient space, as will be 
shown farther on in connection with the subject of the growth 
of the jaw. 

Similar phenomena attend the cutting of the permanent inci- 
sors of the upper jo iv, with the 

exception that, in consequence ~tt— * I,, - b 

of the greater difference in size | 

between the milk and permanent -^Lr' 
incisors, the upper permanent 
lateral, before it is cut, has a 
still greater inclination than the 
under one toward the median 
line and posteriorly. Hence 
still more space must be pro- 
vided in the upper jaw than in the lower, for the eruption of 
the permanent incisors (Fig. 26). 

The first bicuspids generally are the next to take their places 
in the dental range ; it is not an infrequent occurrence, however, 
for their eruption to precede that of the lateral incisors ; the 
second bicuspids usually succeed the canine teeth. The alveoli 
of the permanent bicuspids of the lower jaw are situated between 
the anterior and posterior root of each milk molar. As the in- 
closed crowns of the permanent bicuspids, taken together, occupy 
less space than those of the milk molars with their diverging 

* Fio. 26. — Front view of the upper jaw, of a child seven years of age, 
presenting an abnormal dentition. The central incisors have descended to 
the level of the dental range; the edges of the lateral incisors are situated 
seven millimetres higher up; the latter also are still inclined somewhat 
toward the median line and backward, and consequently have not yet com- 
pleted their slight rotation. The crowns and the already completed roots of the 
permanent canine teeth are situated high up in the anterior segment of the 
septum between the nasal and maxillary cavities, and are inclined toward 
the median line. The extremities of the roots of the milk canines {a, a), the 
crowns of which are affected with caries, are already absorbed. The first 
permanent bicuspid on the left side (b) has descended nearly to the level of 
the dental range, while the first milk molar on the right side (c) is not yet 
shed, and retains, between its roots, the first permanent bicuspid, the radical 
portion of which is developed to a slight degree. Natural size. 



84 ANATOMY AND PHYSIOLOGY. 

roots, space is reserved anteriorly, after the eruption of the first 
permanent bicuspids, for the permanent canine teeth. As the 
second lower milk molar is considerably larger than the first, 
while the second lower permanent bicuspid is of nearly equal 
size with the first, the roots of the first lower milk molar undergo 
a more notable resorption. In consequence of the fact that the 
permanent bicuspids are embraced by the roots of the milk 
molars, as if by forceps, it is necessary to exercise especial care 
in connection with the extraction of the latter, for if it becomes 
necessary to extract the milk molar on account of its unsound- 
ness before resorption of its roots has commenced, the crown of 
the permanent molar will necessarily be extracted at the same 
time, because it is so tightly embraced by the roots of the milk 
tooth (Atlas, Fig. 15). 

The permanent canine teeth remain within their temporary 
alveoli very deeply imbedded in the under jaw, with their long 
diameters inclined towards the median line, until the eruption 
of the perfectly developed permanent incisors is completed, and 
the first permanent molars with their roots are entirely formed; 
the milk molars, however, have not yet been shed. When, in 
consequence of continued resorption of the root, the milk canine 
tooth becomes so loose that it falls out, the permanent canine 
tooth necessarily is slightly tilted laterally on its long axis, be- 
comes more upright, and enters directly into the space left vacant 
by the lower milk canine. Since, however, the latter space is too 
small, the space reserved after the succession of the first bicuspid 
now comes into play. The position of the upper canine teeth 
in their temporary alveoli, is analogous, that is to say, their 
long diameters are inclined somewhat toward the median line, 
and the developing roots, together with the large rounded crowns, 
are implanted in the osseous wedge (Knochenzwickel) between 
the facial wall of the upper jaw, and the septum of the nasal 
cavity and antrum of Highmore. The canines, when inclosed 
in their bony capsules, occupy the highest position of all the 
teeth in the upper jaw, and their crowns experience, in their de- 
scent, a slight lateral tilting, by means of which their crowns 
acquire a more perpendicular direction. 

When the first molars have emerged completely, the prepare- 



SECOND DENTITION. 85 

tions for the eruption of the second molars are completed. The 
jaws have increased in length in their posterior segments, and 
oval apertures are perceptible upon the summit of the alveolar 
process behind the first molars. In the lower jaw, these apertures 
are at the base of the coronoid processes and, in the upper jaw, 
in the upper part and to the outside of the tuberosities. From 
the posterior margins of these apertures extends a more or less 
distinct, shallow, short, narrow, bony groove, which is known as 
the posterior dental groove. About the end of the eighth year 
the apertures enlarge, and the coronal cusps of the second molars 
may be seen at the bottom of them. If the facial wall of the 
jaw and the corresponding segment of the rounded alveolus be 
removed, the lateral portion of the incomplete crown will be ex- 
posed. The subsequent phenomena attending the growth of 
these teeth are similar to those attending the development of 
the first molars. The process, however, is slower, their eruption 
not being completed until the twelfth or thirteenth year, making 
an interval of five to six years between the eruption of the first 
and second molars. 

The above-mentioned posterior dental groove, ascending from 
the base of the coronoid process, and bending upwards like a 
bow over the tuberosity, bears a striking resemblance to the 
dental groove in the jaw of a three months' foetus. It is cov- 
ered with a delicate mucous membrane. At a later period there 
appears in the posterior segment a small crypt (Alveole) about 
the size of a millet-seed, which is intended for the third molar, 
or ivisdom tooth. A spicula of bone, the unabsorbed remains 
of the outer extremity of the alveolus, frequently is found, 
at this period, attached to the outer edge of the aperture pro- 
duced by resorption, and continues to obstruct the entrance to 
the alveolus of the second lower molar. Concurrent with the 
expansion of the crypt-like depression for the wisdom tooth, an 
osseous lamina is developed behind the alveolus of the second 
molar, the alveolar septum, which gradually becomes more 
prominent. About the twelfth year the alveolus of the wisdom 
tooth, shaped like a shallow dish, attains the size of a small 
lentil, but still is situated high up in the tuberosity of the upper, 
and in the base of the ascending coronoid process of the lower 
jaw. As the growth of the posterior segments of the jaws is 



86 ANATOMY AND PHYSIOLOGY. 

advanced considerably, which process takes place much more 
slowly than in the earlier years, the alveoli of the wisdom teeth 
begin to advance, and finally reach the level of the dental range. 
In the meantime the alveoli of their crowns have become deeper 
and wider, and the coronal cusps become perceptible in the 
apertures upon the alveolar processes and gradually become 
larger by resorption. Their eruption occurs, as is well known, 
a few years before or after the twentieth year of life. 

The opinion is entertained by some that the germ of the 
wisdom tooth is derived from a process of that of the second 
molar. But the facts which have been mentioned that, as the 
growth of the posterior segment of the jaw advances, the mucous 
membrane becomes extended over the posterior dental groove, 
and that the development of the alveolus of' the wisdom tooth 
occurs within the latter, are much more in favor of the view 
that the germ of the wisdom tooth, like those of the other teeth, 
is the product of the formation of a sac and papilla? directly 
from the epithelium and corium of the mucous membrane. I 
have been unable to obtain histological evidence in proof of the 
latter theory, yet I consider it, nevertheless, as probable. Ac- 
cording to the recent statements of Kollmann,* the enamel 
germs of the second and third molars are not developed directly 
from the epithelium of the oval cavity, but from the enamel germ 
of the first molar. f 

* Op. cit. 

f The second dentition sometimes does not commence until the second or 
third decade. D. Fricke, of Liineburg (Deutsche Yierteljahresseh. f. Z., 
1869), saw two girls, one eighteen and the other sixteen years old. both of 
whom still retained all the twenty milk teeth which were worn away very 
much. 

[The permanent teeth usually appear at about the following ages, and in 
the following order : 

First molars, . . . . 6th to 7th year. 



Central incisors, 
Lateral incisors, 
First bicuspids, 
Second bicuspids, 
Canine, . 
Second molars, 
Third molars, 



7th to 8th " 

8th to 9th " 

9th to 10th " 

10th to 11th - 

11th to 12th » 

12th to 14th •• 

17th to 21st " 

T. B. H.] 



THIRD DENTITION. 87 

Third Dentition. — The possibility of the occurrence of a 
third dentition is doubted, and even openly denied by many. 
Its opponents assert that cases of presumed third dentition are 
merely instances in which the teeth have not emerged, but have 
remained imbedded within the jaw until the occurrence of senile 
resorption of the, alveolar processes. Deceptions may easily occur 
in regard to them, particularly among the ignorant, as will be 
evident from reference to the section upon the retention of 
teeth. On the other hand, however, we ought not to persist in 
the denial of the occurrence of a third dentition, on the ground 
that it is contrary to the current physiological doctrines. 

The writers of former times,* Aristotle, Eustachius, and Al- 
binus, mention a repeated renewal of the teeth. In recent times, 
Fauchard, Bourdet, J. Hunter (the latter observed a third set 
of teeth in both jaws), Van Swieten, Haller, collected several 
such cases from different writers. Hufeland describes a case 
which came to his knowledge. In the one hundred and six- 
teenth year of life, new teeth were said to have made their ap- 
pearance ; six months after the loss of these, new molars appeared 
in each jaAv. Serres observed two cases in the Hopital de la 
Pitie; one of a man thirty-five years old, whose two lower cen- 
tral incisors fell out, and were replaced after a few months ; the 
other of a man seventy- six years old, who, during convalescence 
from a bilious fever, experienced pain and swelling in the gum 
of the under jaw, which disappeared on the eruption of a tooth 
with several eminences in the place of the second molar on the 
left side. The margins of the alveoli had not yet disappeared in 
this old man. 

C. A. Harrisf has no doubt that a third dentition does occur 
in extremely rare cases, and instances a number of examples 
where individuals, who for a long time had been toothless, ac- 
quired several teeth, or even an entire set, in extreme old age. 
According to the authority of Dr. Bisset, of Knayton, twelve 
molars made their appearance in a woman ninety-eight years 
old. Harris himself observed two cases, the second of which is 

* Carabelli's and Linderer's Geschichte der Zahnheilkunde. 
f Principles and Practice of Dental Surgery. Phil., 1850. 



88 ANATOMY AND PHYSIOLOGY. 

worthy of note, where four central incisors made their appear- 
ance, one after the other, on one side of the upper jaw. Such 
teeth, he remarks, seldom lie in alveoli, and have either no roots 
or stunted ones. He thinks it not improbable that duplicatures 
of the mucous membrane occur during the healing process which 
ensues after the extraction of one or more teeth. M. Carre 
relates the case of a woman eighty-five years old, who cut a left 
upper canine, and a few months later, a left lateral incisor and 
first bicuspid on the right side in each jaw.* Heider reported 
a case of multiple formation of a dwarfish canine tooth in a wo- 
man not very old.f 

If we admit the occurrence of a third dentition in very rare 
cases, it is by no means necessary to assume, as Harris thinks, the 
origin of a new dental germ after the permanent teeth have been 
detached, since it cannot really be denied that germs may lie 
dormant for many years in the animal organism, until they are 
subjected to favorable conditions which enable them to develop. 
The possibility that during a long series of years a germ may 
remain dormant in the lateral folds of the enamel gum, cannot 
be rejected on theoretical grounds. Kollmann even asserts that 
the germs for such a late dentition have their origin in the ear- 
liest years of childhood. The fact that the crowns only are 
formed while the roots are stunted is clearly due to the small 
depth of the jaws in old age. 

Growth of the Jaws. — Ossification of the upper jaw com- 
mences at a very early period. Sappeyt describes five centres 
of ossification. As the ossification advances, sutures make their 
appearance, which directly disappear again. The most con- 
spicuous suture, easily distinguished both in the foetus and in 
the first years after birth, and even later, is the sutura ineisiua, 
which extends from the foramen incisivum across to the septum, 
between the alveoli of the lateral incisor and canine. In rare 
cases it is also continued upon the facial wall of the upper jaw, 
between the above teeth, and can be traced into the nasal pro- 
cess as far as the inner portion of the inferior margin of the 



* Med. and Surg. Reporter, 18*50. 
t Vide Anomalies of Formation. 
X Anatomie Descriptive, 2d ed. 



GROWTH OF THE JAWS. 89 

orbit. The alveolar portion of the upper jaw is divided by it 
into a smaller anterior segment, which includes the sockets of 
both incisors, and a larger posterior segment, which contains 
the remaining sockets. In such cases its analogy with the os 
incisivum of mammals is evident. The deformity known as 
wolf's jaw denotes a persisting fissure between the intermaxil- 
lary bone and the rest of the alveolar process. In hare-lip these 
bones are united, but the fissure of the upper lip persists, corres- 
ponding in its position to that of the junction of the bones. If 
the two upper jaws are not united at the palatal suture, the de- 
formity known as cleft palate results. These malformations 
are considered to be the results of arrest of development, the 
cause of which is unknown. 

The lower jaw is formed very soon after the collar-bone. Ac- 
cording to Sappey (op. cit.), it has two centres of ossification, 
which make their appearance about the thirty-fifth day. In the 
foetus, the lower jaw is divided into two halves, which are not 
wholly united until some time in the course of the first year after 
birth. With a deformity of a median fissure of the lower lip, a 
persistence of the median separation of the lower jaw is observed 
only in a slight degree or not at all. 

The direction of the growth of the under jaw may be ascer- 
tained in part from the direction of the rays of bone. The 
latter may be seen in an embryo, extending along the facial 
wall from the head of the articulating process, which, as yet, 
projects scarcely above the level of the alveolar border, and in 
front of the margin of the ascending ramus, in horizontal and 
somewhat oblique directions towards the anterior segment of 
the maxillary arch ; the latter are joined by those descending 
from the coronoid process which, as yet, is but slightly devel- 
oped. The first-mentioned rays become closely compacted, es- 
pecially in the vicinity of the lower border of the jaw, which 
thereby increases in thickness. The inferior dental canal pri- 
marily is open above like a groove. The growth of the lower 
jaw is most conspicuous -upon its facial wall and inferior border. 
The radiation of the bone is not distinctly marked on its lingual 
surface, where are formed instead imbricated lamellae or delicate 
networks of trabecule. Another centre of ossific radiation 



90 ANATOMY AND PHYSIOLOGY. 

during embryonic life, which easily escapes observation, is 
beneath the mental foramen. Here the osseous trabecular are 
arranged in a crescentic form around the inferior margin of the 
foramen. A similar radiation, with the convexity of the cres- 
cent turned downwards, may be seen about the infraorbital for- 
amen in the upper jaw. 

Towards the end of the third, and the beginning of the fourth 
month after birth, the articular process of the under jaw in- 
creases considerably in length, and the formation of the neck 
portion takes place. By a corresponding growth of the cor- 
onoid process, the saddle-like concavity of the sigmoid notch 
becomes more distinctly marked. At about this period, a third 
svstem of osseous rays is met with, which at a later period 
becomes more apparent, and extends downwards from the head 
of the condyle to the obtuse angle of the under jaw. 

At birth, the lower jaw generally is still separated into its 
two halves. The facial surface of the future symphysis presents 
a triangular, fibro-cartilaginous portion, in which several ossific 
centres appear during the first months after birth. Coincident 
with the latter occurs the union of the two halves, together 
with the formation of the mental process ; the former takes 
place from below upwards and is completed at the period of 
the eruption of the central incisors. 

At birth, the angle of the lower jaw presents only a slight 
bend. Upon the convexity of this curve the osseous substance 
is deposited subsequently in such a manner that the vertex of 
the angle gradually becomes more pointed (during a year or 
year and a half). The angle formed by the junction of the hor- 
izontal and ascending rami changes but little during this time, 
but in the subsequent years it gradually becomes smaller by the 
deposition of bone in increasing proportion from the head of 
the condyle towards the vertex of the angle, while the ascend- 
ing branch, at the same time, gradually increases in length. 

Previous to the eruption of the second milk molar, the growth 
of the posterior segment in length makes considerable progress. 
When the growth necessary for the milk teeth is completed, a 
delicate, porous, osteophyte-like osseous layer is observed upon 
the posterior segment of the inferior maxillary arch, and also 



GROWTH OF THE JAWS. 91 

upon the tuberosity of the upper jaw. The growth in thick- 
ness takes place principally upon the inferior border of the 
lower jaw, that in height is displayed in the fan-shaped ossific 
radiation in the alveoli, and likewise in their ascending septa. 
The spongy substance of the bone between the alveoli and the 
maxillary wall is not developed at first, and the latter lie in 
juxtaposition until the growth of the bone in thickness is con- 
siderably advanced, when the spongy substance makes its ap- 
pearance. In the first and second years after birth, the exter- 
nal and internal oblique lines, together with the spina ment. int., 
&c, are rendered more prominent by means of increased mus- 
cular action. 

Changes in the Jaws during the Second Dentition. — Hunter* 
was the first to assert that in the portions of the jaws in which 
the milk teeth are placed growth ceases after the completion of 
the first dentition. Foxf agreed with him substantially. They 
reached this conclusion by measurements of macerated lower 
jaws. Delabarre,J on the other hand, endeavored by means of 
clinical observations to establish the fact of the growth of the 
bone in length after the first dentition. He asserts that, at the 
age of five to six years, the milk teeth separate from each other, 
and says, that those people with whom this does not occur are 
liable to have an irregular second dentition. Fox had recog- 
nized this occurrence before Delabarre, but did not give to it 
the same significance, for he states, "the anterior portion of the 
jaw undergoes scarcely more than an alteration in form ; it 
adapts itself to the permanent teeth there situated, and scarcely 
receives any increase in size." Th. Bell§ asserts emphatically 
that no reliance can be placed upon the comparison between 
jaws of different individuals. The only way to get at the truth 
of the matter is to examine the same jaw at different ages, and 
then compare the various results. " This," says Bell, "I have 
repeatedly tried, and do not hesitate to say that the ten front 
permanent teeth occupy a somewhat w T ider arch than the milk 
teeth which preceded them." C. A. Harris || coincides with 

* Natural History of Teeth. f Natural History of Human Teeth. 

% Seconde Dentition, 1819. 

\ Anatomy, Physiology, and Diseases of the Teeth, 1835, 2d ed. 

[| Op. cit. 



92 ANATOMY AND PHYSIOLOGY. 

Bell's opinion, and states that the transverse and perpendicular 
dimensions of the anterior portions of the bone continue to aug- 
ment until the completion of the second dentition, and even 
during youth. J. Tomes inclines to Hunter's opinion, and op- 
poses the idea of an interstitial growth of the bone. 

According to Huter,* the growth of the inferior maxillary 
arch in its perpendicular dimensions is chiefly periosteal, while 
horizontally it is the result of the expansive osseous growth. 
In his opinion no notable growth takes place after birth in the 
whole of that part of the lower jaw between the third grinders 
(first permanent molars). Welcker's measurements, also, con- 
firm this statement. Hliter opposed the idea of an interstitial 
growth of bone, while Rich. Volkmann, long since and again 
recently, f advocated its occurrence. C. Ruget and Julius 
Wolff,§ also, are in favor of the same view. I, myself, agree 
with the latter, for the reasons already given. 

There can be no doubt that, as already stated, an enlargement 
of the maxillary arch is produced chiefly by the deposition of 
osseous substance upon the facial surface, and also by resorption 
which takes place upon the lingual surface. In this way the 
front teeth are pushed forward, and the back teeth outwards. 
This change of the location of the teeth, however, is conceivable 
only in case resorption also takes place in the interior of the 
bone, since, otherwise, the teeth, covered as they are by new 
layers upon the facial surface, must finally be pressed nearer 
the lingual surface, which evidently is not the case. An inter- 
stitial resolution must, therefore, take place. Fox advocates, 
to be sure, a change of form in the maxillary arch during its 
growth, but this is true only of the upper jaw. If we compare, 
he says, the jaw of a child with that of an adult, a marked dif- 
ference will be observed; that of the child has nearly the form 
of a semicircle, while that of the adult presents a semi-ellipse. 
These changes in the maxillary arches will be considered at 
greater length farther on.|| 

In order to ascertain the relative groivtli in the under jaic. we 



* Virchow's Archiv, 9 Bd. f Centralblatt fur med.. Wiss 

t Virchow's Archiv, Bd. 49. \ Centralblatt fur med.. Wi- 

ll Vide p. 95, et seq. 



GROWTH OF THE JAWS. 93 

must first endeavor, if possible, to select points that are not 
liable to change, from which to make our measurements. It is 
self-evident that absolute accuracy is impossible, and that ap- 
proximate results only can be obtained. The unavoidable errors 
of observation acquire greater importance the smaller the dis- 
tances which are to be measured. The longitudinal dimensions 
are much less difficult to ascertain than the transverse and 
perpendicular. 

I instituted a series of measurements of forty-five children's 
skulls, with reference to the growth in length of the inferior 
maxillary arch, partly also with the view of ascertaining the in- 
dividual differences, making use of a thin slip of paper slightly 
moistened and accurately adapted to the peripheral surfaces. 
Measurements taken by means of a pair of compasses give a 
sector, when applied to a curved object, which may be the same 
with different curves. The mental foramen is taken as a fixed 
point for measurements upon the anterior segment of the lower 
jaw ; it must, however, be remembered that the locality of this 
aperture is not constant. In the under jaws of adults its ante- 
rior margin falls sometimes in a line between the two bicuspids, 
at times directly under the first, or under the second bicuspid, 
and at others on a line with the posterior coronal surface of the 
second bicuspid. These variations, even in a small series of 
under jaws, give an error of from three to four millimetres. 
Disregarding the latter, and employing the measurements of 
the peripheral distance from the line of junction of the two 
halves of the under jaw (which may easily be marked with a 
pencil) to the anterior margin of the mental foramen, we found 
that, in a five months' foetus, the distance measured 10 mm.; in 
new-born children, 12 to 13 mm.; in children from 4 to 11 
months old, 15 to 18 mm. ; in others from 1 to 7 years old, it 
remained about the same, 18 to 19 mm. ; in four cases, one a 
child 1 year 5 months 27 days old, who had cut the central 
incisors, it reached a length of 20 mm. ; in one 1 year 10 months 
10 days old, with a first molar cut, 21 mm. ; in a child 5 years 
old, with its complete set of milk teeth, 21 mm. ; in one 6 years 
1 month old, with a large set of teeth, 23 mm. ; from 7 to 12 
years, inclusive, it varies from 22 to 24 mm., and in comparative 



94 ANATOMY AND PHYSIOLOGY. 

measurements of adults' under jaws, between 23 and 29 mm. 
If # we disregard extreme cases, we find the most notable growth 
of this part of the tinder jaw during the first months of life, and 
an interval of rest after the eruption of the milk teeth, and again 
an increase during the shedding of the teeth, amounting to at 
least 3 mm. In order to meet the objection, that no account 
was taken of the thickness of the facial wall, separate measure- 
ments were made after the removal of the facial Avail ; they 
showed, however, as indeed was anticipated, no material difference. 
Further measurements were made, in the same manner by 
means of a slip of paper, of the whole length of the facial sur- 
face of the under jaw from the junction of the halves, which was 
marked, to the most prominent point of the condyle, which may 
be done as* long as the latter does not project very far above 
the level of the alveolar margin. This peripheral boundary 
measures, in a foetus of five months, 40 mm. ; in one of 7 months, 
43 mm.; in a new-born child, 45 to 52 mm.; it increases until 
the fourth month to 58 mm.; till the seventh month to 62 mm. ; 
till the first year to 67 mm. ; till the end of the second year, 
after the eruption of the first molar, to 77 mm. ; in the fourth, 
fifth, and sixth years, with the entire set of milk teeth, from 78 
to 85 mm. ; in a child seven years old, with the first permanent 
molar, to 100 mm. After this age such measurements cannot 
be made with precision. If we subtract from the latter the 
measurements of the anterior segments of the two halves of the 
lower jaw, made from the median line as far as the anterior 
margin of the mental foramen, we obtain a series of measure- 
ments for the posterior segments, from the last-named margin to 
the prominent point of the condyle. This latter series gives an 
increase of from 30 to 77 mm., while we found that the anterior 
segments increased from 10 to 23 only. The total increase rep- 
resented by the quotients of the latter, 2.56 and 2.3 respec- 
tively, presents a difference which is due to the greater degree 
of growth of the posterior segment of the jaw. J. Tomes em- 
ployed also the tubercles on the lingual surface of the lower 
jaw, which serve for the attachment of the c/enio-Jit/o-glossus 
and genio-hyoideus muscles, as a point from which to take meas- 
urements. According to my experience, however, these tuber- 



GROWTII OF THE JAWS. 95 

cles are, often, so indistinct in the foetus, and likewise in the 
new-born child, and vary so mujch in form, size, and height in 
children, and particularly in adults, that the value of such 
measurements appears doubtful, and all the more so in the case 
in hand, from the fact that the calculation involves such small 
quantities. 

. Measurements of sets of teeth, taken on the facial margin of 
the alveolar border, from the line of junction of the jaws across 
the necks of the teeth to the posterior portion of the neck of 
the second bicuspid, gave for half the set of lower milk teeth, 
32 to 34 mm.; the peripheral extent of the permanent teeth, 
measured in the same manner, varied from 32 to 37 mm. In 
many cases, therefore, the size of the under set of milk teeth 
conforms exactly to the corresponding segment of the perma- 
nent set ; in some cases the former may even be larger, but 
generally the reverse is the case. 

Just as the new layers of bone are deposited upon the facial 
wall of the growing maxillary arch, and resorption takes place 
upon its lingual surface, so in the development of the posterior 
segment of the jaw, deposition of new osseous layers takes place 
upon the posterior surface of the articular and osseous process, 
while anteriorly upon the coronoid process and condyle resorp- 
tion of the osseous substance ensues. G. M. Humphrey* has 
proved this fact experimentally. He introduced wire ligatures 
through the middle of the ascending ramus of the lower jaw of 
a young pig, near the anterior and posterior margins of the 
ramus, and ascertained that, after the expiration of a certain 
interval, the front loop was loose and projecting, while the back 
one lay deeply imbedded within the posterior portion of the 
ramus. He states that a somewhat analogous process occurs 
in the upper jaw, and, on the whole, agrees with the views of 
J. Tomes. 

In order to illustrate the changes ivhich take place in the arch 
of the milk teeth, in comparison with that of the permanent 
teeth, the arches formed by a permanent and milk set and that 
of the outer alveolar plate of a seven months' foetus, placed one 

* Transactions of the Cambridge Philosophical Society, vol. xi, part 1. 



96 



ANATOMY AND PHYSIOLOGY. 



inside the other, were employed as a basis for measurements. 
The commencing and terminal points of the measurements were 
as' follows : The centre of the space between the edges of the 
two central incisors, and the points of the intersection of the 
posterior coronal with the masticating surfaces of the crowns of 
the second permanent bicuspids and milk molars, and, in the 
seven months' foetus, the point of junction of the two halves of 
the jaw, upon the facial alveolar margin, and the outer extremity 
of the alveolus for the second milk molar. As they were made 
upon a well-developed set of milk teeth and a large set of a 
man twenty-two years old, they are not the mean measurements 
and have no claim to a very general application. 



Fig. 27. 




In the upper jaw (Fig. 27), it will be seen that the curve 
a, a f , obtained by the above measurements in a seven months' 
foetus, is very nearly the segment of a circle ; in the milk set, 
6, b' ', it describes a concentric arc of a circle ; in the permanent 
set, on the other hand, it has changed into the segment of an 



* Fig. 27.— Diagram illustrating the changes in the dental arch during 
the growth of the upper jaw. (a), lowest point in the junction of the anterior 
portions of the two segments of the upper jaw, from a ftetus in the seventh 
month ; (6), central point of the space between the edges of the two central 
incisors of a set of milk teeth; (c), the same of a permanent set ; (a' . pos- 
terior and external termination of the alveolus for the second milk molar ; 
(&'), point of intersection of the posterior coronal with the masticating sur- 
face of the second milk molar; (c'), point of intersection of the posterior 
coronal with the masticating surface of the second permanent bicuspid. 
Natural size. 



GROWTH OF THE JAWS. 



97 



ellipse, c, c'. We find, further, that the point a has advanced 
to b and finally to <?, anteriorly, while posteriorly the displace- 
ment of a' to b' measures the same as that of a to b, but that 
the point c' is displaced comparatively farther outwards; in 



other words, a, b 



b', but 6, c < b,' c f . The permanent 



second bicuspid occupies a more outward position towards the 
face than the permanent central incisor. 

A similar method was applied to the lower jaw (Fig. 28), and 
it was found that, in corresponding segments, the increase in 
growth is less than in the upper jaw, and that the curves con- 




tinue nearly parallel, that is to say ab = a f b f , and b c=b f c' nearly ; 
the second permanent bicuspid is placed only a little farther ex- 
ternally than the second milk molar, and does not, as is the 
case in the upper jaw, undergo a- notably greater facial displace- 
ment than the central permanent incisor. If a moderately 
well-developed set of permanent teeth be chosen and compared 
with a large, well-developed set of milk teeth, the curves 5, V 
and c, c' coincide, and the latter curve may be met with even 
smaller than the first. 



* Fig. 28. — Diagram illustrating the change in the dental arch, during the 
growth of the lower jaw ; a, the highest point in the line of junction of the 
anterior surfaces of the two segments of the lower jaw in a foetus of seven 
months. The rest of the letters indicate corresponding points with those in 
the last figure. Natural size. 

7 



PART II. 

PATHOLOGY. 

I. IRREGULARITIES IN THE FORMATION OF TEETH. 

The teeth are subject to manifold anomalies which are de- 
serving of careful consideration, since, in addition to the mere 
theoretical interest which they possess, many require a special 
operative treatment. 'They present for particular consideration 
abnormal conditions in respect of size, number, arrangement, 
position, and structure. The permanent teeth will be considered 
first, since their irregularities are the more important and of 
more frequent occurrence. 

1. Irregularities of Size. 

Excessive size, so great as to constitute a disfigurement, is 
seldom presented by the entire rows of permanent teeth, more 
frequently by the front ones alone. With this condition, the 
crowns of the upper central incisors are particularly conspicuous, 
in consequence of their very great extent of surface, while 
their roots remain comparatively short and stunted. Sometimes 
the excessive size of the upper central incisors is compensated 
for by the lesser, retarded growth of the laterals. Occasionally 
the excessive growth involves both the crowns and the roots of 
the canine teeth, which then resemble the fangs of animals. 
Disproportions in size between the jaw and teeth are accom- 
panied by corresponding changes in the arrangement of the 
latter which will be considered at length in subsequent pages. 

Excessive growth is limited to one or another tooth, and 
must not be confounded with the excessive size occasioned by 
the coalescence of two teeth, the incisors, for example, a mis- 
take very easily made, since the longitudinal groove which is 



IRREGULARITIES OF NUMBER. 99 

produced by the coalescence of the teeth is perceptible on the 
roots only, and not upon the blended crowns. 

On the other hand, teeth may not attain the average size, 
and still there may be no interruption in the contiguity of the 
dental range. If, however, the maxillary arch is too wide, in 
proportion to the dental arch, intervals occur now and then be- 
tween the teeth, especially between the front ones. These in- 
tervals will be so much the more conspicuous, if either of the 
front teeth is unusually small in comparison with the others. 
They occur most frequently between the two upper central, and 
lateral incisors, and more rarely between the lower centrals. 
The interval between the two upper centrals is often so wide, 
and occasions such a disfigurement that Heider was required 
frequently to fill up the abnormal space by the insertion of a 
tooth. In many cases, these large intervals are occasioned by 
the prolonged retention of a large milk incisor, which prevents 
the normal advance and approximation of the two permanent 
incisors. Generally, however, they are due to the great resist- 
ance of the alveolar septum, or the suture which unites the two 
segments of the upper jaw. Wisdom teeth, particularly, are 
liable to be stunted in their growth. 

In many children, milk teeth are found so uncommonly large 
and strong, that they may easily be mistaken for permanent 
teeth, and on the contrary, in others, they are remarkably 
small, and at times, the milk incisors, for example, do not 
afford surface enough for the application of an ordinary pair of 
children's forceps, without danger of grasping the contiguous 
tooth at the same time. When the milk teeth are too large, the 
incisors, in particular, frequently overlap one another on account 
of the deficiency of space. Milk canine teeth, both in the 
upper and lower jaw, sometimes are unusually long and pointed. 

2. Irregularities of Number. 

Deviations from the normal number occur more frequently 
with the permanent than with the milk teeth, and a number of 
teeth less than normal is observed more often, perhaps, than 
the opposite condition. J. Tomes, on the contrary, asserts that 
an excess of the normal number is perhaps more common. 



100 PATHOLOGY. 

The excess of the normal number of teeth is either absolute, 
that is to say, there are more than the thirty-two normal teeth 
present ; or it is relative if there is an excess of one or another 
kind, while the total number does not exceed, and, indeed, 
may even be less than the normal number. If it is desired 
to enumerate accurately the number of teeth in a set, it is 
not sufficient to give merely the total number of teeth existing, 
but the different kinds of teeth should be enumerated sepa- 
rately, and then all the teeth together. An adult may have 
the requisite number of thirty-two teeth, and still present both 
a deficiency and an excess of one or more teeth. It may happen 
that the upper jaw contains two supernumerary lateral incisors, 
while the wisdom teeth are wanting. Hence the total number 
is not altered but remains thirty-two, and yet there is an excess 
and a deficiency of two teeth to be specified. 

Supernumerary teeth may be divided into two groups, those 
which can be ranked with one or another of the members of the 
dental series, and those which differ in form from the latter, 
called the conical teeth (Dutten-oder Zapfenzahne). 

Those belonging to the first group are, most frequently, inci- 
sors and bicuspids. Sometimes five, and in very rare cases, six 
incisors instead of four are met with in one jaw. The super- 
numerary tooth usually is a lateral incisor, and generally is so 
well arranged in the series that this anomaly easily escapes ob- 
servation, especially in the under jaw. 

An extra canine tooth has been observed, but it is a very un- 
common occurrence. The cases in which a milk tooth is re- 
tained in later life in close proximity to a permanent one, 
evidently do not belong to this class, but are liable to be misin- 
terpreted by an inexperienced observer. Heider observed a 
remarkable case, that of a woman who had several canine 
teeth in succession, which, to be sure, were stunted in their 
growth. Three months after he extracted the well-developed 
canine, which had become diseased, a hard body, resembling 
the latter, made its appearance in the upper part of the socket, 
upon the external surface of the gum. It was of the size of a 
rice-kernel, and its extremity was covered with enamel. About 
the same interval having elapsed after the extraction of the 



IRREGULARITIES OF NUMBER. 101 

latter, a second, and finally a third appeared, so that in the 
course of a year three such canines, each provided with its root, 
were extracted from this woman's jaw. When three, instead 
of two, bicuspids are met with, the supernumerary one gener- 
ally stands inside the dental range, towards the tongue, crowded 
into the space between the two normal bicuspids, so that to- 
gether they form an equilateral triangle. In rare cases, three 
bicuspids are met with on each side, but scarcely ever three in 
the upper and under jaw at the same time. 

Wisdom teeth are sometimes duplicated, one standing within, 
and the other without the dental 
range. The latter is always the 
supernumerary tooth, occurs 
upon the outer side of the one 
in the range, and generally has 
a much smaller crown and a 
stunted, roundish root. Super- 
numerary molars are extremely 
rare, and still more rare is their 
arrangement in the normal den- 
tal row, as in the case of a set, 
belonging to a negro, which, be- 'f ^ v 

sides four molars in each maxil- 
lary segment, contained a supernumerary bicuspid, making 
altogether five teeth more than in the normal condition (Figs. 
29 and 30). This case suggests further inquiry, whether super- 
numerary molars occur more frequently, and anomalies of posi- 
tion more rarely, and also whether the anterior segment formed 
by the inferior dental arch is more circular, and the jaws longer, 
in the negro than in the Caucasian race?f 

* i'lG. 29. — Shows supernumerary molars in the upper jaw, from the skull 
of a negro (for the use of which the author is indebted to Prof. Langer). 
The set of teeth is remarkably well developed and regular. Behind the three 
large, well-developed molars, upon the right side, the wisdom tooth is placed 
in the dental range ; on the left side it has not yet protruded, but is imbedded 
in the tuberosity, and may be seen in the opening made in the part. Two- 
thirds natural size. 

f J. Mummery (Transactions of the Odontological Society of Great 
Britain, New Series, vol. ii) ascertained that with the Ashantees, the 




102 PATHOLOGY. 

An excess of normally-shaped milk teeth is occasioned, usually, 
by one or another supernumerary incisor. 

Fig. 30.* 




The second group of supernumerary teeth includes the so- 
called conical teeth, which can be ranked with neither of the 
four kinds of teeth. They resemble most the canine teeth in 
form, though there is no danger of confounding the two. In 
most cases the crown, as well as the invariably single root, is 
conical, and the three dental tissues are well developed ; the 

inhabitants of Dahomy and a few neighboring tribes on the west coast of 
Africa, the dental arches are very wide, and adduced the frequent occurrence 
of supernumerary teeth among them as a noteworthy fact. He observed 
six cases, in each of which there was a fourth extra molar in the upper jaw, 
in five of the cases on both sides, and in the other on one side; three cases 
of an extra third upper bicuspid on one side; an extra upper canine tooth 
in a regular position on each side, and an extra well-developed right upper 
central incisor. In the under jaw he did not meet with a single example of 
a supernumerary tooth, but the third molars were frequently larger than the 
second. 

* Fig. 30 shows three supernumerary teeth in the lower jaw. from the 
same negro's skull. The arrangement of the dental row is regular. On the 
left side, and lingual surface, between the two bicuspids, lies a supernumerary 
bicuspid, which is twisted so that its lingual coronal surface is turned towards 
the median line of the jaw. The wisdom teeth on both sides are located 
behind the three large molars. Two-thirds natural size. 



IRREGULARITIES OF NUMBER, 



103 



exposed upper surface is encircled, sometimes, by transverse 
grooves; the pulp-cavity is elongated into a single dental canal. 
In rare cases the crown is three-sided, resembling a pyramid, in 
which cases the root, also, presents similar surfaces, but the planes 
of tho- coronal surfaces correspond to the edges of the roots 
(Atlas, Fig. 1).* Sometimes these teeth are disproportionately 
short and thick, bat ordinarily they are slender, and present 
many variations in respect of size. 

Their locality is variable; they are placed either among the 
permanent teeth in the dental 
range, or, as is generally the 
case, stand upon one side of 
the latter. They are found 
implanted between the central 
upper incisors (Fig. 31), or 
between the upper centrals 
and laterals, frequently be- 
hind the centrals or laterals, 
or in pairs on the palatal por- 
tion of the upper jaw, and 
also at the side of the bicus- 
pids or molars in both the 
upper and lower jaws. They 
seem never to occur in the vicinity of the lower incisors. 

Their eruption takes place during the first or second dentition, 
or in the interval between the two. J. Tomes reports two cases, 
which occurred in his practice, of supernumerary conical teeth 




* Fox, Nat. Hist, of the Human Teeth, p. 69, with instructive illustrations. 

f Fig. 31 shows a supernumerary tooth situated at the right side of the 
median line and between the central incisors of the upper jaw. It has a 
conical crown, is well covered with enamel, and somewhat worn away trans- 
versely at the extremity. The incisors upon the right side slightly overlap, 
while those upon the left side stand within the dental range. The right 
segment of the dental arch extends about three millimetres more posteriorly 
than the left, on account of the insertion of the supernumerary tooth. The 
latter probably emerged sooner than the right incisors, and produced only 
a slight variation in the dental arrangement, on account of the breadth of 
the maxillary arch. Two-thirds natural size. (The author is indebted to 
Prof. Langer for the use of this specimen.) 



1Q4 PATHOLOGY. 

in children five years of age. In most cases, however, they 
belong to the second dentition, and are permanent. The ques- 
tion as to whether they are secondary developments from the 
germs of milk or permanent teeth may be answered negatively, 
inasmuch as they differ in shape from normal teeth. Reasoning 
from the latter point of view, it is more probable that they are 
independent dental germs, products of the superficial mm 
membrane, and do not originate, like the permanent teeth, from 
secondary germs. 

As their eruption is coincident, generally, with that of the per- 
manent teeth, they are more likely to interfere with the regular 
arrangement of the latter when the maxillary arch is too narrow 
or too short, and are the origin of a variety of anomalies in the 
position of teeth. As they occasion a disfigurement, and inter- 
fere with articulation when they are situated in the palate, in 
which case also the tongue is especially liable to injury, further, 
as they favor the occurrence of caries when they are placed by 
the side of bicuspids or molars, and, finally, as tip 
particular service, if allowed to remain, it 
tract them. A thorough acquaintance with them, then 
indispensable to the practitioner. In cases where th< 
numerary teeth are well arranged in the dental row between the 
central incisors, or occupy the position of lateral incisors, it is the 
common practice to allow them to remain, since in the former 
case a disfiguring oblique position of the permanent teeth 
be anticipated under any circumstances, ami in the latter it 
not be expected that the sockets of the supernumerary teeth 
will be filled up by a lateral displacement of the remaining teeth. 
The treatment is to be determined only by a careful considera- 
tion of the circumstances in each case. 

The extraction of such teeth from their alveoli is attended 
with no difficulty, on account of the favorable form of their r 
but the adaptation of the forceps is sometimes interfered with in 
certain localities. 

Deficiency of Teeth. — Cases of the absence of all the perma- 
nent teeth certainly are very rare. Linderer* reported tin 

* Zahnheilkunde. p. 137. 



IRREGULARITIES OF NUMBER. 105 

of a woman fifty years of age, who never had any teeth. The 
examination of her mouth gave no grounds for doubting the 
truth of her assertion. J. Tomes* relates one or two similar 
cases, though in his practice he has never met with a person 
who did not present some indication of second teeth. Carabelli,f 
also, never observed such a case ; and he asserts that the entire 
absence is an improbable, though not an impossible occurrence. 
Heider, in the course of twenty-three years, never met with an 
instance of total deficiency. 

Sometimes, though rarely, very many of the permanent teeth 
are tvanting, the whole set containing but a few teeth. Such 
cases now and then come under the observation of extensive 
practitioners and are referred to in nearly all the larger works 
on dentistry. Fox saw a young woman about twenty years of 
age, who retained the central milk incisors of the under jaw 
and, in the upper jaw, all the milk incisors except one lateral, 
which had fallen out. He also relates a case in which there 
were only four teeth in each jaw, and still another, in which 
there was but one incisor in the upper jaw. J. Tomes relates 
an instance where there was one molar on each side of the upper 
and lower jaw. These four molars, together with four incisors, 
two in each jaw, composed all the permanent teeth. It is a 
curious fact that the milk teeth presented no peculiarities in 
regard to their number, or the time at which they were shed, 
according to the statements of the patient and his friends. 

The absence of single permanent teeth is not of rare occur- 
rence. The utmost caution is requisite in judging in a given 
case, whether a tooth is wanting naturally or has been detached, 
since the statements of patients are exceedingly untrustworthy; 
sometimes they cannot remember which teeth, if any, have been 
extracted. A thorough examination of the teeth, which remain, 
of the sockets and jaws, is necessary before coming to a decision. 
Especial attention should also be given to the fact whether such 
defects are hereditary or not, for it often happens that the same 
tooth is deficient with several members of the same family. 

Individuals are met with, now and then, who have only one 

* Op. cit., p. 206. f Anatomie des Mundes, p. 127. 



106 PATHOLOGY. 

large incisor in the upper jaw, which mars considerably the sym- 
metry of the dental range. When this is seen, it may be as- 
sumed, almost with certainty, that the second incisor, now 
missing, formerly stood in its place, and was lost by a blow, 
fall, &c, soon after it was cut. Heider mentions a case which 
occurred in his practice, where a surgeon, after extracting an 
upper central milk incisor, the root of which was entirely ab- 
sorbed, mistook the projecting extremity of the permanent in- 
cisor for the broken root, seized it, and consequently extracted 
the entire immature, secondary tooth. Afterwards the parents 
brought the latter secondary tooth to him, to be replaced in the 
child's jaw, but this, of course, was impracticable, with the root 
only half developed. 

Many similar mistakes are liable to be made with the rest 
of the milk teeth, and the fact that these pass unnoticed in so 
many cases, accounts for the frequent deficiency in the number 
of the secondary teeth, particularly when it is considered that 
the gaps which remain after the extraction of teeth at such an 
early age are entirely effaced by the approximation of the suc- 
ceeding teeth, so that the dental range presents a complete ap- 
pearance, and, in such cases, many are entirely ignorant of the 
fact of the loss of a tooth, thinking nature failed to produce a 
secondary tooth. 

In many cases the lateral incisors are wanting upon one side 
only, but a deficiency upon both sides is of more common occur- 
rence. Of the canines, sometimes one is absent in the upper or 
under jaw, or both are wanting and, almost always, are concealed 
within the jaw, as in the case, Atlas, Fig. 4. Sometimes only 
one bicuspid is present upon one or both sides, and generally 
that is the first ; the second bicuspid is often absent, but usually 
it is concealed in the jaw, its eruption being prevented by want 
of space, since it is obliged to emerge between the first bicus- 
pid and first molar. As is well known, sometimes the upper, 
and, at others, the under wisdom tooth is out of sight entirely, 
perhaps on account of the non-formation of the germs, or. it may 
be that they lie imbedded in the jaw and are prevented from 
emerging in consequence of want of space, which latter is fre- 



IRREGULARITIES OF NUMBER. 107 

quently the case with the lower wisdom teeth, on account of the 
marked projection of the coronoid process in front. 

The inspection of the relations of the locality and thorough 
examination of the neighboring sockets and portions of the jaw 
will indicate whether disproportion of space hinders the develop- 
ment of the tooth, or whether the latter is actually wanting. 
By a careful examination of the jaw with the finger, the bulging 
corresponding with the location of the concealed tooth may 
frequently be felt distinctly, and often furnishes presumptive 
evidence in regard to the position of the latter. Operative in- 
terference should very seldom be decided upon at once ; an 
attempt should not be made to provide room by the removal of 
permanent or milk teeth which stand in the way, until, after 
repeated examinations, there remains no doubt about the exist- 
ence of a concealed tooth, the position and development of which 
may be assumed to be normal, with a considerable degree of 
probability, upon the ground of the prominent bulging of the 
jaw which has been mentioned. 

The absence of all the milk teeth is allowed to be an occur- 
rence of extreme rarity. J. Tomes* has never had the oppor- 
tunity of examining such a case, either in a living subject or in 
a prepared specimen. He was informed, recently, by a gentle- 
man, that a member of his family, a female about fifteen years 
of age, had been from the time of her birth, and was then, en- 
tirely edentulous, and that the lower part of her face preserved 
the appearance usually presented by a child before the eruption 
of the teeth. 

A diminution in the ordinary number of milk teeth is not so 
rare ; generally in such cases the lateral incisors are absent. 
In regard to this anomaly, however, it is to be borne in mind 
that the deficiency of one or another tooth may only be appar- 
ent, since, in consequence of the contracted space their erup- 
tion may be utterly impossible, or else they can emerge only 
partially. Suppuration of a dental sac or alveolus, which occurs 
in scrofulous children particularly, involves, of course, the de- 
struction of the corresponding tooth, and deserves mention in 
connection with the subject of the deficiency of teeth. 

* Op. cit , p. 39. 



108 pathology. 

3. Irregularities of Arrangement. 

A. Irregularities in the Arrangement of the Entire Dental 
Arches. — In the deviations of the set from the normal position, 
which occur in the Caucasian races, either the upper or the 
lower jaw, or both together, are more or less elongated ante- 
riorly ; their alveolar processes describe an unusually broad or 
narrow, oval or circular arch ; the undulatory curves of the 
dental arches are more shallow or deeper than is the case ordi- 
narily; the six anterior sockets of one or both jaws are more 
everted or inverted ; the teeth, implanted in these sockets, have 
very long or short, broad or narrow crowns, and the latter are 
well or badly arranged ; the dental arch presents an abnormal 
internal or external curvature, together with a frequent want of 
symmetry between the two halves of the jaw ; the molars pre- 
sent an excessive mesial or lateral inclination, and the ascending 
ramus of the lower jaw is too short or too long. These exam- 
ples of the principal irregularities which occur in the position 
of sets of teeth, give rise also to various deviations from the 
normal conformation of the mouth. 

a. Sometimes all the incisors and canine teeth, particularly 
those in the under jaw, instead of being arranged side by side, 
in the form of an arch, are placed in a straight line so that the 
canine teeth meet the bicuspids nearly at right angles. The 
lower half of the face thus loses its oval curve, becomes broader, 
and gives rise to the flat mouth. A less degree of this irregu- 
larity is produced very frequently by a slight overlapping of 
the crowns of the lower incisors. 

b. If the middle portions of the two alveolar arches project 
forwards considerably, and, at the same time, are everted, then 
the canine teeth and incisors, implanted in these portions, will 
also project obliquely forwards, and this gives rise to the so- 
called negro mouth (os sethiopum). As, with this irregularity, 
the front teeth in closing come together obliquely, or not at all, 
the pressure and counterpressure necessary for their fixation 
■cannot take place, and consequently such teeth emerge gradu- 
ally from their cells, appear to grow longer, and finally fall out 
much earlier than others. 



IRREGULARITIES OF ARRANGEMENT. 109 

c. The alveolar process of the upper jaw is often unusually 
deep and very prominent; the teeth implanted in it being 
very long and generally broad, the incisors and canines are 
pushed outward so far, that between them and the under teeth 
there is left a vacant space, in some cases five or six lines in 
width; frequently the palatal arch forms a sharp curve and is 
narrow, and the upper bicuspids and molars are everted, al- 
though to a less degree than the front teeth, so that merely 
their internal coronal cusps and the outer coronal edges of the 
corresponding under teeth come in contact ; in these cases, the 
labial fissure is wide and the upper lip usually very short ; the 
inferior maxillary arch presents a contracted appearance ; when 
the mouth is closed, the lower lip lies behind the upper front 
teeth, and the lower incisors impinge upon the posterior gingival 
portions of the upper teeth. As with such an arrangement of 
the dental arches, and such a misshaped mouth, a person ex- 
poses nearly all the upper teeth, together with the anterior por- 
tion of the upper gum, especially in speaking and laughing, this 
deformity is usually call the grinning mouth (Fletschenmund). 
J. Tomes* calls attention to the fact that, in most of these 
cases, the molars are unusually short, and finds that there is a 
short alveolar process, and a short rectangular ascending ramus 
of the lower jaw. This conformation he regards as probably 
the primary cause of this deformity. G. Prochaska,")" in a skull 
presenting an irregularity in the position of the teeth, in which 
the lower incisors stood three lines behind the upper ones, when 
the jaws were approximated, observed that the convexity of the 
superior alveolar arch, in comparison with that of the under jaw, 
was unusually great. 

d. Sometimes the lower incisors and canine teeth are half an 
inch in advance of the corresponding teeth of the upper jaw, 
and, in such cases, the crowns of the lower front teeth fre- 
quently are so deep as entirely to conceal the upper incisors, 
when the jaws are closed. The prominent under lip overlaps 
the contracted upper one, and the chin is thrown forwards. 



* Op. cit, p. 124. 

f Observ. Anat. de Decremento Dentium, 1800. 



110 PATHOLOGY. 

This deformity is produced by a want of relationship between 
the superior maxillary arch, which is shorter, and the inferior, 
which is longer, than in the normal condition, and by an exces- 
sive development of the alveolar portion of the lower jaw. 
According to Grynnel, a natural, partial luxation, which takes 
place at the articulation of the lower jaw, is also to be taken 
into account, as contributing to its production. The deformity 
of the mouth which it occasions is called " underhung" (das 
Hundemaul) (la ganache of the French). 

e. When the six upper front teeth are placed directly over 
the lower ones, so that their respective incisive margins meet 
edge to edge, there results the so-called upright set, one of the 
most frequent irregularities, and accompanied, usually, by the flat 
mouth. This position of the teeth is very favorable for masti- 
cation, for, in biting, the teeth act in a perpendicular line and 
become firmly pressed into their sockets, and the masticating 
surfaces operate to the best advantage, while the teeth are not 
so likely to be loosened as is the case when the front teeth are 
everted ; on the other hand, they are subjected to more wear 
from attrition, so that the incisive edges and points become 
transformed into small masticating surfaces. 

/. Another irregularity of the dental arches occurs when the 
incisive margins of the front teeth meet edge to edge, but both 
the upper and under incisors are inverted, producing a sort of 
channel, opening outwards, where the dental arches are in con- 
tact. In these cases, the chin projects very much, and the lips 
are considerably retracted. The mouth shaped by this irregu- 
larity is called, from its resemblance to that of an old person, 
the senile mouth (os senile). 

g. Cases in which the mouth remains open continually, in which 
the sets of teeth stand apart, form a very disagreeable and trou- 
blesome deformity. Many people cannot bring together the 
anterior portions of the two rows of teeth, so that between the 
upper and under incisors there remains a space from two to 
ten millimetres in width. This space, between the two rows of 
teeth, gradually becomes smaller from before backwards, as far 
as the second molars, the masticating surfaces of the latter being 
partly, while those of the wisdom teeth are wholly in contact 



IRREGULARITIES OF ARRANGEMENT. Ill 

with those of the opposite teeth. This repulsive arrangement 
of the two dental arches is due, generally, to a short articular 
process of the lower jaw, as a result of which the anterior seg- 
ment of the inferior maxillary arch and the chin assume an 
unusually depressed position. Less frequently, the reason 
may be found in an irregular conformation of the alveolar 
process, the posterior alveoli of which are much higher, in- 
stead of lower, than the anterior ones. Still more rarely is it 
due to a curve or an oblique direction of the lower jaw from 
behind forwards and downwards. It might be attempted also 
to refer this deformity to the crowns of the last molars, but as 
the latter are always found unusually low, it is evident that the 
evil will not be remedied by filing or by extracting them. 

h. C. Langer* mentions a form of want of relationship between 
the dental rows which occur in giants ; the jaws are developed 
in height nearly in proportion to the rest of the body, and the 
size and shape of the lower jaw, especially, assume really mon- 
strous proportions, the latter exceeding in its development that 
of the upper jaw to such an extent that its dental row frequently 
forms a wide arch which envelops that of the latter. The 
smaller the cranium so much the more marked is this monstrosity 
of the under jaw. 

i. In cases of asymmetrical development of the two halves 
of the same jaw, the set of teeth presents a distorted appear- 
ance, and projects more or less, either obliquely upwards or 
downwards upon one side or the other. 

To recapitulate, the irregular (abnormal) sets comprise, a, 
those which are flattened in front ; b, those in which both the 
upper and lower ranges project ; c, those in which the upper 
row is most prominent ; d, those in which the lower is most 
prominent; e, the upright sets ; f, those in which both rows are 
inverted; g, those in which the two rows are separated in front; 
h, those in which the lower row is too broad; i, the distorted 
sets. These include the principal forms, between which innu- 
merable varieties may occur. The latter are the more frequent, 
since complex cases occur so often, which combine irregularities 
in the position of the entire set with those of separate teeth. 

* Sitzungsber. der Wiener Akad. d. Wiss. vom, 1 Juli, 1869. 



112 PATHOLOGY. 

B. Irregularities in the Position of the separate Permanent 
Teeth. — The irregularities in the position of separate teeth may 
arise from several causes : 1. From the growth of the jaws being 
absolutely insufficient in proportion to the space required in the 
maxillary segments for the corresponding teeth. It has been 
shown in connection with the growth of the jaws, that the an- 
terior portions of the maxillary arches grow comparatively less 
than the branches upon either side, subsequent to the eruption 
of the milk teeth, and, therefore, it is easy to understand that 
irregularities in the position of the anterior permanent teeth 
are of more frequent occurrence ; 2. From a disproportion be- 
tween the very wide maxillary segment and the small crowns of 
the teeth ; 3. From an interruption in the process of shedding 
the teeth ; when a milk tooth is retained, the corresponding per- 
manent tooth is forced to take another position ; 4. From an 
irregularity in the process of shedding the teeth, that is, when 
one or another tooth is shed and replaced prematurely, the adja- 
cent secondary tooth is compelled to adopt another position; 
5. From the early removal of a permanent tooth, in which case 
the socket cicatrizes and, consequently, the adjacent permanent 
tooth, which has not yet emerged, is compelled to assume an- 
other position ; 6. From the existence of an unabsorbed alveolar 
cicatrix, resulting from the premature shedding or extraction of 
a milk tooth, which forces the secondary tooth to take another 
position ; 7. From an anomalous position of the milk tooth, which 
necessitates an irregular position of the permanent tooth ; 8. 
From the partial or complete occupation of the place of a per- 
manent by a supernumerary tooth ; 9. From an exostosis upon 
the alveolar process, especially upon its posterior segment ; 10. 
From abscesses of the alveoli of the milk teeth ; 11. From the 
presence of tumors within the jaws, collections of pus, &c. 

Commonly the following irregularities are presented : The 
long diameter of the tooth is inclined too much externally or 
internally towards the median line of the jaw or laterally,' and 
frequently, if there is sufficient space to allow it, the* tooth 
assumes a nearly horizontal position. The tooth may undergo 
a quarter or half revolution upon its long axis. The intervals 
between certain teeth and the adjacent ones may either be too 



IRREGULARITIES OF ARRANGEMENT. 113 

wide or too narrow, and in the latter case the teeth sometimes 
partially overlap their neighbors either upon the facial or lin- 
gual surfaces. 

Central Incisors. — A slight degree of irregularity in position 
is presented by an unusually wide separation of the adjacent 
teeth, which occurs less frequently with the lower incisors. 
These large intervals, which frequently amount to a deformity, 
in many cases are occasioned by the protracted retention of a 
large milk incisor, which prevents the normal emergence and 
approximation of the two permanent incisors. Generally, how- 
ever, they are due to the firmness of the suture which unites the 
two segments of the upper jaw. 

Twisting of the central incisors upon their axes is by no 
means of rare occurrence. This _ „- 

FlG. 32* 

may take place in the direction 
of the median line or laterally, 
to various degrees, 45°, 90°, and, 
in rare cases, even 180°. Ac- 
cording to the manner and extent 
of the revolution, the labial sur- 
face becomes turned towards the 
adjacent central or lateral incisor, 
and, in rare cases, it is changed 

so as to look towards the tongue. The torsion is generally lim- 
ited to one central incisor, but instances are recorded in which 
each has experienced a twisting upon its axis (Fig. 32). 

By a lateral inclination of the central incisors the crowns fre- 
quently overlap. Sometimes the central incisors are inserted 
more or less towards the hard palate, or the lips. In many cases 
one of them stands outside the range anteriorly, and the other 

* Pig. 32 shows a twisting of both central upper incisors, occasioned, 
probably, by a hyperostosis in the palatal suture. The labial surfaces of 
both permanent central incisors are turned laterally, the lingual towards 
the median line ; the lateral milk incisors are twisted laterally at an angle 
of nearly 45° ; the milk molars are in their normal positions ; the first 
permanent tooth has emerged. The maxillary arch is narrow. Natural size. 
(From a plaster cast, for the use of which the author is indebted to Prof. 
Strasky.) 





114 PATHOLOGY. 

posteriorly, so that the lower incisors are inserted between the 
two when the jaws are closed. The upper incisors are frequently 
inclined posteriorly. 

The causes of these mal-positions are numerous. The reten- 
tion of the central milk incisor 
FlG - 33 -* or its root, the premature ap- 

pearance of the lateral perma- 
nent incisor, which offers an im- 
pediment to the growing tooth, 
or perhaps an arrest of develop- 
ment in the corresponding por- 
tion of the jaw, or a super- 
d a numerary tojoth (Fig. 33), may 

be cited as predisposing causes. 
As the tooth during its growth must adapt itself to the space 
provided for it, so does its eruption ensue regularly, or a mal- 
position occur in accordance with the dimensions of the space it 
is to occupy. 

Lateral Incisors. — The axial torsions of these teeth occur 
almost always in such a manner that their labial surfaces are 
turned, to a slight degree only, towards the median line of the 
jaw, or laterally, and consequently are overlapped by, or them- 
selves overlap, the lateral borders of the central incisors. 

The torsion may amount to 90°, and in rare cases it reaches 
180°. The lower laterals are more frequently the subjects of 
slight rotations than the upper ones. When the latter are in- 
volved, their axes are directed towards the canine teeth or the 
central incisors. It frequently happens that they are implanted 



* Fig. 33 shows a displacement of the upper front teeth on the right 
side, produced by a supernumerary tooth. The front teeth upon the left 
side of the broad upper jaw were quite normally arranged, while upon the 
right side a conical supernumerary tooth (a) occurred within the dental 
range, adjacent to the left central incisor ; this pressed the right central in- 
cisor (b) forwards and upwards. The lateral incisor (c) is twisted upon its 
axis, so that its labial surface is turned laterally. The milk canine tooth 
(d) is retained, and the permanent one (e) is implanted without the dental 
range, toward the face. Natural size. (From a plaster cast, for the use of 
which the author is indebted to Prof. Strasky.) 



IRREGULARITIES OF ARRANGEMENT. 



115 



Fig. 34.* 




at the side of the dental range, either upon the facial or lingual 
side, the latter mal-position being 
most marked in narrow wedge-shaped 
upper jaws. In the latter, which 
commonly are asymmetrical, the lin- 
gual surfaces of the central incisors 
face each other, and the lateral in- 
cisors are implanted behind the den- 
tal range at a greater or less dis- 
tance from the palatal suture (Fig. 
34). 

Marked mal-positions of the front 
teeth are produced very often by the presence of supernumerary 
teeth in the anterior portion 
of the upper jaw, since the 
latter are the first to make 
their appearance and interfere 
with the eruption of the nor- 
mal teeth (Fig. 35). 

In the under jaw it is not 
uncommon to find the lateral 
incisors implanted upon the 
lingual side of the dental 
range; sometimes they stand 
directly behind the central 
incisors (Atlas, Fig. 138), and 




* Fig. 34. — A wedge-shaped narrow upper jaw of a young person, in 
which both lateral incisors have emerged upon the lingual side of the dental 
range, in consequence, perhaps, of some interruption in the development of 
the jaw, or, it may be, from the protracted retention of the lateral milk in- 
cisors. The right milk canine tooth has fallen out. (From a plaster cast.) 
Two-thirds natural size. 

f Fig. 35 shows an asymmetrical conformation of the upper jaw in 
which two supernumerary teeth are implanted behind the displaced incisors. 
The right maxillary wall bulges forwards in front, and, between the first 
molar (a) and the second bicuspid (6), presents a flexion towards the median 
line. A deviation of the dental arch, therefore, occurs at this point, and the 
front teeth on this side, the canine (c) and the laterally twisted lateral in- 
cisor, stand in a straight. line. The central incisor, upon the right side (e), 
which has not emerged completely, is located upon the median line. The 




116 PATHOLOGY. 

at other times they present a combination of axial torsion and 
mesial or lateral inclination (Fig. 36). 

Probably the most frequent predisposing causes of these 

irregularities of position are to be 
found in the development of the 
osseous tissue in the anterior seg- 
ment of the jaw, which may be too 
slow to correspond with the growth 
of the permanent teeth, or may be 
arrested, or abnormal in its dimen- 
sions. The developing crowns will 
be found, even within the dental sacs, in abnormal positions. 
A protracted retention of the lateral milk. incisors or canine 
teeth, or the premature cutting of the permanent canines, may 
occasion irregularities, and the latter may crowd the lateral 
incisors, before they are properly and firmly fixed, towards the 
median line of the jaw, or towards the tongue, and sometimes 
may even occasion resorption of the extremities of the roots of 
the latter teeth. If the canine tooth emerges upon the lingual 
side of the dental range, it may press the lateral incisor towards 
the lips. 

Canine Teeth. — Irregularity in the position of these, especi- 
ally of the upper ones, occurs frequently ; they are situated 
more or less without the dental range and overlap the lateral in- 
cisor or first bicuspid, either upon the facial, or, more rarely, 

left central incisor is implanted upon the left side, and the left lateral incisor 
upon the lingual side of the left canine tooth (/). (From a plaster cast.) 
Two-thirds natural size. 

* Fig. 36. — Anterior segment of the lower jaw. Tiew from the lingual 
side. The two lateral incisors are implanted behind the centrals, are twisted 
and inclined towards the median line of the jaw, and, together with the 
centrals which are inclined laterally and considerably worn away upon 
their coronal edges, inclose a quadrilateral space. As the lateral incisors 
are implanted behind the dental range, and their edges are below the level 
of the masticating teeth, they have not been employed in mastication and, 
indeed, do not in the least present any indications of abrasion. These irreg- 
ularities of position were produced by an interrupted development of the 
jaw and, perhaps, a premature eruption of the canine teeth, which are very 
much worn away upon their coronal extremities. Natural size. 



IRREGULARITIES OF ARRANGEMENT. 117 

upon £he lingual surface. In the latter case, after the complete 
emergence of the crown of the canine tooth, there occurs an 
outward displacement of the lateral incisor or first bicuspid. 
The inclination of the axes of the canines usually is towards 
the median line of the jaw. They are frequently twisted upon 
their axes to a slight degree and, in rare cases, present quarter 
and half revolutions. A quarter revolution of the crown, be- 
fore it has cut through the gum or before the formation of the 
root is completed, may prevent the eruption of the tooth, since 
the facio-lingual diameter of the crown in this position is rela- 
tively too great to enter between the lateral incisor and first 
bicuspid. The canine tooth, 
therefore, remains concealed . FlG ' 87 '* 

within the jaw, on account of 
its abnormal torsion. Some- 
times the canine tooth aban- 
dons its proper place entirely, 
and is found by the side of the 
central incisor (Fig. 37), in 
which case the lateral incisor 
is located either upon the lin- 
gual or lateral side of the displaced canine tooth. Much more 
rarely, the canine tooth is inserted between the two bicuspids. "f 
The frequent irregularities in the position of canine teeth 
may readily be explained when we consider that their normal 
eruption is provided for by the vacant spaces w T hich remain 



* Fig. 37 shows a displacement of the upper left canine (a) to the side of 
the central incisor. Posterior to the former is an alveolar cicatrix, prob- 
ably the remains of the socket of the lateral incisor which emerged subse- 
quently to the canine. Upon the right side, the canine occupies its normal 
position; the lateral incisor (&) is stunted; the bicuspids upon either side 
retain their normal positions. Natural size. (For the use of this specimen 
the author is indebted to Dr. Friedlowski.) 

f The museum of the Harvard Dental School contains a cast taken from 
the mouth of a young woman, in which the left inferior lateral incisor and 
canine are transposed, the canine being turned so that its labial surface is 
presented towards the central incisor and the median line, while its lingual 
surface is presented towards the lateral incisor and backwards. 

Another cast of the lower jaw of a person about sixteen years of age pre- 
sents the canines between the second bicuspids and first molars. — T. B. H. 





118 PATHOLOGY. 

between the first bicuspids and lateral incisors, after the latter 
have already assumed their positions, and that these spaces are 

too narrow when the growth 
of the jaw in length is sus- 
pended. A premature or de- 
layed eruption of the perma- 
—6 nent canines, a protracted re- 
tention of the milk canines, 
sometimes even to the third 
decade of life, or the inser- 
tion of a supernumerary tooth 
in the dental range, may also 
give rise -to these displace- 
ments (Fig. 38). 
Bicuspids and Molars. — The first bicuspids seldom, the second 
more frequently, are met with without the dental range and 
generally in the so-called small or anterior oval cavity. A prem- 
ature loss of the second milk molar promotes the advance of 
the first permanent molar, in consequence of which the second 
permanent bicuspid is forced to emerge either upon the facial 
or lingual side of the dental range. In many cases, one or 
both bicuspids are twisted in such a manner that their cusps 
become located anteriorly and posteriorly, instead of externally 
and internally (Fig. 39). Insufficient space is, almost always, 
the predisposing cause. 



* Fig. 38 shows displacement of both canines produced by the reten- 
tion of the milk canines, and by the presence of a supernumerary tooth. 
The upper jaw is broad and has an irregular conformation. The central in- 
cisors are slightly inclined to the left side, where the milk canine (a), worn 
away by attrition, is seen, adjacent to the central incisor, while the lateral 
is located upon the lingual surface behind the milk canine ; the permanent 
canine (b) is in the dental range, in front of the first bicuspid. Upon the 
right side, the lateral incisor is in the dental range ; the permanent canine (c) 
is inserted without the dental range, towards the face ; the milk canine, the 
crown of which is considerably worn away, is crowded towards the tongue. 
Between the canine and the first bicuspid, on either side, is a supernumerary 
tooth (d), the crown of which is very much worn away. Behind the central 
incisors are seen lunated folds of mucous membrane. Two-thirds natural 
size. (From a plaster cast, for the use of which the author is indebted to 
Prof. Strasky.) 



IRREGULARITIES OF ARRANGEMENT. 



119 



Fig. 39.f 



J*- » 'V 1 



An axial revolution of 180° is extremely rare. Werner* 
states that in those cases, in which the milk molars are retained 
with the permanent bicuspids, the latter assume 
an oblique position. J. Tomes observed a dis- 
placement of the bicuspids, resulting from caries 
of the milk molars, which was followed by an 
alveolar abscess, and also axial rotations of the 
second bicuspids, occasioned by the retention of 
the palatal root of the second milk molar. The 
lower bicuspids sometimes stand so far apart, 
in consequence of the great abundance of room, 
that a person unacquainted with the true condi- 
tion will be convinced either that teeth existed previously, or 
are to appear, in this interspace. 

The notable derangement which supernumerary teeth occasion 
in the position of the nor- 
mal teeth, when they occur 
in the anterior segments of 
the jaws, may also extend 
so far as to involve the bi- 
cuspids, particularly the « 
second, which generally in 
such cases are implanted 
towards the tongue (Fig. 
40). 




* Anomalien der Zahnstellung. Inauguraldissertation, Giessen, 1868. 

f Fig. 89 shows a segment of the right half of the upper jaw. The 
two bicuspids are placed close to one another with their facial surfaces 
twisted posterior^ about 90° ; the first is crowded somewhat externally, and 
is in contact with the second, which is pressed slightly towards the tongue. 
Natural size. 

X Fig. 40 shows marked displacement of the upper incisors, canines, and 
bicuspids, occasioned by two large supernumerary teeth. The two central 
incisors are implanted upon the lingual side of the dental range, the left 
slightly overlapping the right in front ; the left lateral incisor (a) is located 
outside the dental range towards the face ; behind the right lateral (b) is 
located the first bicuspid. Two conical supernumerary teeth (c) and (d), 
which are worn away upon the crowns, have emerged on the side towards 
the lips. The first bicuspid on the right side (e) is twisted several degrees 
towards the median line of the jaw, the second is inserted upon the lingual 



120 



PATHOLOGY. 



An arrest of development in the posterior segments of the 
jaws sometimes occasions a displace- 
ment of the three molars, by which 
they are inserted so as to form a 
triangle. Wisdom teeth, especially 
those in the under jaw, when their 
roots are imbedded in the coronoid 
process, not infrequently are in- 
clined anteriorly to a considerable 
degree towards the second molars, 
with the posterior coronal surfaces 
of which their masticating surfaces 
come in contact.. Frequently their 




crowns present a lingual, and, 



more rarely, a facial inclination. 
In the upper jaw, the wisdom teeth are inserted sometimes high 
up towards the tuberosity, and the masticating surfaces may 
even face posteriorly. Slight displacements of these teeth with- 
out the dental range, generally to the lingual side, are of fre- 
quent occurrence. 

Marked irregularities in the position of the molars, accom- 
panied, at times, by deformity of the upper jaw, are produced 
by a hyperostosis upon the alveolar process (Fig. 41). t 



side of the dental range. Upon the left side, the bicuspids are separated 
somewhat from each other by an angular interval which opens externally, 
and in which projects the coronal portion (/) of the canine tooth. Two-thirds 
natural size. (From a plaster cast, for the use of which the author is in- 
debted to Prof. Strasky.) 

* Fig. 41 shows a narrow upper jaw, as if compressed from side to side. 
Plaster cast. The six front teeth, with the exception of the left lateral inci- 
sor which is implanted upon the lingual side of the dental range, are ranged 
in contiguity so as to form a very narrow arch, the arms of which are nearly 
parallel to each other. Three molars present a curved arrangement forwards 
and outwards. The extremity only of the crown of the first right molar (?) 
has emerged. Distinct folds of the mucous membrane are perceptible, and 
also hyperostoses on the lingual aspect of the posterior segments of the al- 
veolar process, which diminish the breadth of the channel-like cavity formed 
by the high arch of the hard palate. Two-thirds natural size. 

f In the Dental Pveview (1859), a curious instance is mentioned of the mal- 
position of a wisdom tooth between the upper incisors. A. zur Xedden 
(Deutsche Yiertelj. f. Z., ]868), obtained a plaster cast of an upper jaw in 



IRREGULARITIES OF ARRANGEMENT. 121 

Irregularities in the Position of Milk Teeth. — The milk teeth 
are very rarely met with without the dental range, and only in 
those cases in which all the milk teeth are very large, when, in 
consequence of a deficiency of space, the incisors overlap. In 
many cases the sharp edges of the upper incisors are inclined 
very much towards the tongue, and the canines, uncommonly 
long and pointed, are crowded towards the face. 

In extremely rachitic individuals, abnormal positions of milk 
teeth are frequently met with, since in these cases the growth 
of the jaws in length is retarded by a hyperplasia of the con- 
nective tissue in the bone (Atlas, Figs. 144 and 145). In the 
latter case, moreover, it is to be observed that, although the 
process of decalcification has made such progress in the bony 
structure that the latter has become flexible and may be cut 
with a knife, it has not in the least affected the crowns and the 
growing roots of the teeth. The development of the tooth, there- 
fore, continues, notwithstanding the notable interruption to the 
growth of the bone. If the rachitis does not become very de- 
cided until after the milk teeth are cut, then the permanent 
teeth, still inclosed in the dental sacs, may be displaced from 
their normal positions. 

Abscesses of the periosteum of the root, which occur particu- 
larly in scrofulous children and sometimes after cutaneous erup- 
tions, may produce considerable destruction of the bone, dis- 



which a molar occupied the place of a central incisor, neither of the normal 
incisors being present. 

All teeth which are inserted upon one side of the dental range, or overlap 
the anterior or posterior contiguous teeth either upon the facial or lingual 
surface, are very liable to be affected with caries, because, even with the 
utmost cleanliness, the particles of food cannot be removed entirely from 
the intervals between the teeth. Moreover, it is a very difficult matter to 
apply to them the ordinary methods of treatment, for a tooth, which is in- 
serted externally, cannot be reached upon the inside, and one situated inter- 
nally cannot be reached upon the outside, on account of the close proximity 
of the adjacent tooth. Therefore they require peculiar and extremely diffi- 
cult methods of treatment. When a bicuspid is twisted to the amount of 
90°, the operative treatment is attended with still greater difficulties, because 
the surfaces of its roots are directed outwards and inwards, and consequently 
offer greater resistance b}' reason of their more numerous points of contact 
with the walls of the alveolar process. 



122 PATHOLOGY. 

placements and partial destruction of the milk or permanent 
teeth, which are still inclosed in the dental sac. 

C. Irregularities in the Position of Separate Permanent 
Teeth ichich are Imbedded ivithin the Jaiv. — It sometimes hap- 
pens that a tooth, during its development, acquires a more or 
less inclined or horizontal position, and consequently, when its 
development is completed, projects but little, if any, beyond the 
alveolar wall. The causes of these extremely curious devia- 
tions of position can be ascertained only by a special anatomical 
examination of each individual case. As a general rule, it may 
be assumed that the change of position must occur prior to the 
development of the root. The growth of the latter, modified by 
the local relations, takes place in an opposite direction to that 
of the incisive margin or masticating surface of the tooth whose 
position is changed, i. e., if the masticating surface is inclined 
forwards, the root grows from before backwards. These irregu- 
larities include a great variety, and all the predisposing causes 
which have been mentioned previously are equally applicable to 
them. J. Tomes* illustrates a case in which the crown, as well 
as the root of the right central incisor, is imbedded in an oblique 
position within the bone, beneath the floor of the nasal cavity, 
its normal position being occupied by a supernumerary tooth, 
which, it is obvious, prevented the emergence of the incisor. 

Figs. 2 and 3 of the Atlas illustrate a case in which a well- 
formed lateral incisor occupies a horizontal position in the angle 
formed by the floor of the antrum and the nasal process of the 
upper jaw, its incisive edge projecting through an oval opening 
with smooth edges, at the side of the apertura pyriformis. The 
cause of this displacement is obvious in the presence of an irregu- 
larly formed tooth which is inclosed in a smooth-walled osseous 
capsule, and projects near the edge of the alveolar process, and, 
perhaps, is the rudimentary lateral milk incisor, since its posi- 
tion is directly over that which a milk incisor should occupy ; 
or it may be the shapeless mass of a supernumerary tooth. 

The canine teeth, more frequently than any others, are the ' 
subjects of total displacement, a fact quite easily understood: 
the upper ca nines are more frequently displaced than the lower, 

* System of Dental Surgery, p. 183. 



IRREGULARITIES OF ARRANGEMENT. 123 

as the front teeth of the upper jaw require more space. Albinus* 
describes a case with a canine situated between the nasal cavity 
and the orbit on either side, whose crowns were directed upwards. 
J. Hunterf reports a similar case. Wait observed a case where 
the radical extremity of a canine pierced the gums externally. 
J. Tomes J gives a series of illustrations in which the permanent 
canine is displaced behind the dental range, the root being 
curved very much, or placed across the dental arch, with its 
apex directed towards the median line of the palate, its crown 
towards the cheek and projecting slightly, or in a horizontal 
position, with the coronal apex in front and the root extending 
posteriorly or into the floor of the nasal cavity. 

The succeeding series of figures will serve to illustrate the 
causes of partial or complete perma- 
nent embedment of the canine teeth fig. 42.§ 
within the jaw. In the case, Fig. 42, 
the retention of an upper milk canine 
occasioned a twisting of the crown of 
the permanent tooth, and forced it to 
assume an oblique position, pointing 
towards the median line, so that its 
eruption progressed to a slight degree c a 
only behind the dental range. 

In the under jaw similar conditions are met with. In Fig. 
43 the retained milk canine tooth produced an axial revolution 
of the developing crown of the permanent canine, as in the pre- 
ceding case, and has inclined it towards the horizontal line, so 



* Adnot. Acad., i. f Nat. Hist, of Teeth. % Op. cit. 

g Fig. 42 shows the incomplete eruption, upon the palatal surface of the 
alveolar process, of the crown of the right upper canine which has an oblique 
direction towards the median line. (The specimen is from a young subject, 
and for the use of it the author is indebted to Dr. Friedlowsky.) The per- 
manent incisors and the temporary canine have been detached by maceration. 
The slightly projecting crown of the permanent canine tooth (a) has given 
rise to a sharp-edged opening, the result of absorption, upon the alveolar 
process, and, in the same manner, the corresponding portion of the alveolus 
of the lateral incisor (b), and also that of the milk canine (c), has been ab- 
sorbed. The first bicuspid was slightly twisted by the curved root of the 
permanent canine which is imbedded within the jaw. Natural size. 




m 



PATHOLOGY, 



that its extremity only has emerged beneath the alveolar 

margin. 

A forward inclination and quarter revolution on the part of 
the first bicuspid may also produce an axial revolution of the 
growing canine, and entirely prevent its eruption (Fig. 44). 



Fig. 44.f 




Goethe observed;); in an osteological preparation in the pos- 
session of Rapp, in Stuttgart, 1797, a total displacement of a 
bicuspid which was located in the nasal cavity beneath the 
margin of the orbit, its roots firmly attached to a small, round, 
plaited osseous mass ; it extended obliquely downwards and 



* Fig. 43 shows the anterior segment of the lower jaw in which the left 
canine tooth is placed horizontally beneath the alveolar margin. The coronal 
extremity has emerged upon the lingual wall of the lower jaw (a). The 
labial surface of the crown is upwards. The root is turned obliquely out- 
wards, projects beyond the labial wall of the jaw, and has given rise to re- 
sorption in the corresponding portion of the wall (b). A portion of the 
posterior wall of the alveolus of the left lateral incisor has been removed by 
resorption ; the superior circumference of the alveolus of the milk canine (c) 
is still well preserved. Natural size. 

f Fig. 44 shows a segment of the lower jaw from which a portion of the 
facial wall was removed in order to display the left canine and first bicuspid, 
which are not yet cut. The canine remains in a perpendicular position, and 
its radical extremity (a) reaches to the inferior border of the lower jaw : its 
labial surface is directed forwards and inwards, and its coronal and radical 
portions are in contact with the first bicuspid (b) which, also, is imbedded 
within the jaw, its internal coronal cusps alone being slightly exposed, and 
is inclined anteriorly and twisted on its axis to the extent of a quarter of a 
turn. Natural size. 

j Schweizerreise. 




IRREGULARITIES OF ARRANGEMENT. 125 

backwards, and emerged from the palatal portion of the upper 
jaw behind the incisive canal, where its crown was but slightly 
exposed upon the surface of the palate. J. F. Meckel* met 
with an upper second bicuspid, the crown of which pointed 
directly upwards. The first bicuspid was detached at an early 
period, and there was a large gap between the canine and first 
molar. An abscess of the root- 
membrane of the first milk molar FlG - 45t 
may have given rise to the rota- 
tion of 180°. A nearly hori- 
zontal position of the second left 
bicuspid in the upper jaw, as 
shown in Fig. 45, in all proba- 
bility was occasioned by an in- 
flammation of the periosteum of 

the root of the first molar, which was followed by a destruction 
of the corresponding portion of the alveolus and, without doubt, 
occurred at an early period while the process of shedding the 
milk molars and eruption of the bicuspids was in progress. The 
cicatrization, which encroached upon the territory of the second 
permanent bicuspid, may have been the cause of the deviation 
of its coronal portion, in consequence of which the masticating 
surface became directed backwards and slightly downwards. 
The tooth emerged in the gap in the dental row, while the 
growth of the radical portion took place in a direction forwards 
and a little upwards. By the removal of the alveolar wall it 
was ascertained, further, that the roots of the first and second 
bicuspids were not blended together, since their extremities had 
been kept apart by a thin osseous lamina. 

Abnormally short jaws sometimes contain several permanent 
teeth imbedded within them in irregular positions, which do not 



* Tabulae Anat. Path. Ease, iii. 

f Fig. 45. — Facial view of the left upper jaw. The second bicuspid has 
a nearly horizontal position, its masticating surface being directed towards 
the anterior facial roots of the second molar ; the crown and neck lie in the 
upper part of the alveolar process, within an excavation which probably 
resulted from an alveolar abscess of the first molar. Two-thirds natural 
size. (For the use of this specimen the author is indebted to Prof. Langer.) 



126 PATHOLOGY. 



make their appearance until the occurrence of senile atrophy of 
the alveolar process, and then only partially emerge (Fig. 46). 



Fig. 46.* 




The wisdom teeth are more frequently the subjects of a total 
displacement. The reason for this is quite obvious, from the 
fact that they are the last to take their places in the dental 
series and therefore have reserved for them that space only 
* which remains vacant at the posterior extremity of the jaw. In 
the upper jaw an axial displacement, by which the masticating 
surface becomes directed posteriorly, is the most frequent. If 
the coronal portion is bent from its normal position, so as to 



* Fig. 46 shows a bicuspid upon the right and left side imbedded within 
the short, distorted upper jaw of an old person. On the right side, behind 
the alveolus of the canine tooth (a), the alveolar process becomes prominent 
and presents two cavities, at the bottom of which are seen the two coronal 
cusps of a bicuspid (b), with the longitudinal groove between them extending 
from side to side. Finally, this segment of the jaw also presents the wisdom 
tooth imbedded within the maxillary tuberosity in a horizontal position, 
with its crown directed posteriorly and its roots inserted between those of 
the second molar, as may be seen upon the buccal surface of the maxillary 
wall. Upon the left side cicatrization has taken place in all the alveoli. 
The crown of the bicuspid, however, which is imbedded within the jaw in 
an oblique position, may be seen through the openings resulting from re- 
sorption in the bulging portion of the alveolar process, while its radical 
portion (c) forms an oblique projection upon the buccal surface of the jaw. 
The lower jaw corresponds to that of extreme old age and is edentulous, 
with the exception of one bicuspid. Natural size. (For the use of this 
specimen the author is indebted to Dr. Friedlowski.) 



IRREGULARITIES OF ARRANGEMENT. 127 

describe an arc of 90°, the growth of the roots takes place from 
behind forwards, in a more or less horizontal direction, and the 
latter come in contact with those of the second molar, some- 
times even blend with them, so that the second and third molars, 
by the coalescence of their roots, form an inseparable whole 
(Atlas, Figs. 18 and 19). If now the growth of the roots of the 
wisdom tooth continues from behind forwards, the crown neces- 
sarily emerges posteriorly and, consequently, induces a partial 
resorption, varying in extent, of the maxillary tuberosity of the 
upper jaw. The crown of the wisdom tooth may also be in- 
clined externally or internally, and the roots be placed across 
the jaw in a more or less horizontal position. The rotation 
sometimes amounts to 180°, so that the masticating surface is 
directed upwards and the roots downwards. 

In the lower jaw, an inclination of the crowns of the wisdom 
teeth from behind forwards, is most common, in which cases the 
growth of the roots takes place in the ascending ramus. Wer- 
ner* also mentions cases which came under his observation where 
the lower wisdom tooth assumed a nearly horizontal position, 
the roots being inclined obliquely downwards and backwards, 
and the crown forwards, so that only the posterior and upper 
portion of the crown was visible. Sometimes the germ of the 
coronal portion of this tooth is displaced so far posteriorly, that 
the crown of the tooth becomes imbedded within the ascending 
ramus of the lower jaw, reaching nearly to the level of the sig- 
moid notch. Finally, the crown of the wisdom tooth may be 
the subject of a rotation on its transverse axis to the extent of 
180°, in which case the inverted crown is grasped by the roots 
of the second molar.f 

D. Retention of Teeth without Displacement. — Cases are fre- 
quently met with, where, completely developed permanent teeth 
remain during life, partially or entirely inclosed within the jaw, 
in the places where their development took place. The position 
of such teeth is not really anomalous, and becomes irregular 

* Op. cit. 

f Compare the instructive illustrations given by J. Tomes, op. cit., p. 192 
et seq. 



128 PATHOLOGY. 

only because it persists during the later periods of life. Those 
teeth are most frequently the subjects of this irregularity, which, 
as their growth continues, should occupy the spaces left vacant 
by the already developed adjacent teeth, namely, the canines and 
second bicuspids. The canine tooth, as we know, is obliged to 
insert itself between the permanent lateral incisor and first bi- 
cuspid, after the latter have taken their positions in the dental 
series, and the second bicuspid enters the interval left vacant 
between the first molar and the first permanent bicuspid which 
have already emerged. If, therefore, from any cause a dispro- 
portion exists between the above-mentioned intervals and the 
circumference of the crowns of the teeth which are to occupy 
them, the complete eruption of the canine or second bicuspid 
will be prevented partially or entirely. 

An instructive case is illustrated in the Atlas, Fig. 4, where 
both canine teeth are imbedded within the lower jaw and are 
slightly twisted upon their axes, the right towards the lateral in- 
ci'sor and median line of the jaw, the left laterally towards the first 
bicuspid. The development of the radical extremities of both 
canines, in the direction of their long diameters, was possible 
only to a certain extent, and they are bent at nearly right angles, 
each in a different direction. The case, therefore, is quite com- 
plicated, as it illustrates not only a retention of both canines 
within the under jaw, but also an axial revolution and a deviation 
in the direction of growth of the radical extremities. . The extent 
to which the incisors are worn aw r ay indicates that the specimen 
belonged to a person of advanced age, and so it may be assumed 
that, had all the adjacent teeth become detached and an atrophy 
of the alveolar process ensued, the coronal extremities of both 
the imbedded canines w r ould have made their appearance. Pos- 
sibly the prolonged retention of the milk canines occasioned the 
axial revolution of the permanent teeth and, consecutively, pre- 
vented the eruption of the latter, but this point cannot be de- 
termined. 

Wisdom teeth, especially those of the under jaw, are most fre- 
quently subject to retention. The space necessary for their 
eruption in the maxillary arches, which so frequently do not 
grow to a sufficient length, is preoccupied by the teeth which 



IRREGULARITIES OF ARRANGEMENT. 



129 



have made their appearance, and, therefore, there is no room left 
for the wisdom teeth. Sometimes the upper second molar is 
crowded so far backwards towards the tuberosity, that the fur- 
ther descent of the third becomes impossible. In the same way, 
the space in the lower jaw becomes diminished when the second 
molar is crowded close up to the ascending ramus. In addition 
to the disproportion between the lengths of the maxillary and 
dental arches, special causes, which are not readily distinguish- 
able, also occasion the retention of the wisdom teeth. Some- 
times, during the process of cicatrization which ensues after the 
detachment of the first upper molar, the second molar acquires 
a forward inclination which prevents the emergence of the wis- 
dom tooth, since the posterior external root of the former im- 
pinges upon and opposes the advance of the crown of the latter 
(Fig. 47). 



Fig. 47.* 



Fig. 48.f 



Fig. 494 






* Fig. 47 shows an obstacle to the descent of the right upper wisdom tooth, 
in a facial view of the posterior segment of the upper jaw. The first molar 
was detached some time previously ; the second is inclined anteriorly, and 
the extremity of the posterior facial root (a) has a corresponding deviation 
posteriorly, and presses against the descending masticating surface of the 
wisdom tooth, the facial surface of which (b) has been exposed by the removal 
of the alveolar wall. Two-thirds natural size. 

f Fig. 48 shows the union of the roots of the upper second molar on 
the left side, with those of the wisdom tooth, as seen from the facial side. 
The posterior facial root of the second molar, which has been filed away to 
show the root canal, impinges upon the anterior facial root of the wisdom 
tooth, and is united to it by means of cement ; in the same manner, the 
lingual root of the second molar is united with the anterior facial root of the 
wisdom tooth by means of a quite thick layer of cement. These teeth were 
extracted on account of chronic inflammation of the root-membrane and 
suppuration of the gum. Natural size. (For the use of this specimen the 
author is indebted to Dr. Jurie Grustav.) 

% Fig. 49 shows a union of the posterior facial root of the upper second 



130 PATHOLOGY. 

Sometimes a union of the roots of the second upper molar 
with those of the wisdom tooth, also, prevents the descent of the 
latter. In such cases the wisdom teeth are found in a normal 
position, but are situated one centimetre higher than usual (Figs. 
48 and 49). 

Teeth which are retained within the jaw frequently make 
their appearance unchanged in the later periods of life, when 
their emergence is promoted by the loss of the other teeth and 
by the changes which take place in the jaws in old age. People 
who are ignorant of this fact interpret the occurrence falsely 
as an evidence of remarkable vigor, when, in reality, it is only 
an indication of old age. These teeth always emerge very 
slowly, and are rarely of much value to the possessor. 

4. Irregularities of Structure. 



These involve either all the teeth in common, or a part of them, 
most frequently, however, separate teeth or only their coronal 
or radical portions. In general terms, they comprise growth in 
an abnormal direction ; excessive, stunted, or arrested develop- 
ment of the dental tissues ; the coalescence of two dental germs 
and the blending of roots; monstrous malformations of the 
crowns and roots, and double malformations of the teeth. 

a. Flexions and Torsions of the Crowns and Roots. — In rare 
cases, teeth which have single roots are bent at right or more 
obtuse angles in the coronal portions or in their immediate 
vicinity, while the roots, in these cases frequently stunted, 
retain their normal positions. With the crowns of incisors, rec- 
tangular flexions are most frequently observed, their incisive 
edges being directed forwards or backwards, or inclined to either 
side. "When the crown of an upper incisor is bent towards the 
lips, the palatal surface of the tooth is directed downwards, and 
upwards Avhen the flexion is towards the tongue. The reverse 
is the case with the incisors of the lower jaw. 

molar on the left side with the blended facial roots of the wisdom tooth. 
View from the facial side. Natural size. (For the use of this specimen the 
author is indebted to Dr. Friedlowski.) 




IRREGULARITIES OF STRUCTURE. 131 

The development of a crown which is the subject of this dis- 
tortion may go on to completion ; exami- 
nation of the enamel, however, in the vi- 
cinity of its terminal portions, will show 
a variation from the normal arrangement 
of the layers, inasmuch as the enamel is 
thicker at the vertex of the angle of flexion, 
while the margin of the enamel is furrowed 

in some cases, and raised into a fold in others (Figs. 50 and 51). 
Sometimes cleft-like gaps, lined with very thin layers of enamel, 
are met with, which likewise indicate irregularity and interrup- 
tion in the development of the enamel. These circumstances 
justify the assumption that the flexion takes place prior to the 
completion of the formation of the enamel cap of the crown. 
The growth of the roots may continue in the normal direction 
after the occurrence of flexion of the coronal portions. 

These flexions should be studied carefully by practitioners to 
whom such teeth are presented for the purpose of being straight- 
ened, because the distortion can neither be removed nor im- 
proved, and there is nothing to be done except to extract the 
tooth affected. Care should be taken not to confound cases 
presenting this deformity with those in which normally formed 
teeth assume an oblique or a nearly horizontal position, and 
which, under favorable circumstances, may be treated with suc- 
cess. A careful examination of the teeth and jaws, and par- 
ticularly the existence of slight irregularities upon the crown of 
the tooth in question, for example, notable bulging upon either 

* Fig. 50. — Lateral view of an upper central incisor. The crown is com^ 
pletely developed ; the extremity of the short, thick root is turned towards 
the lips. On the edge of the enamel, on the lingual surface, rises a sharp 
ridge, corresponding to which, upon the labial surface, is a constriction. 
Natural size. 

f Fig. 51. — Lateral view of a lower central incisor. The crown is bent 
at a right angle, so that the incisive edge, with its three denticles, is directed 
towards the lips. The lingual surface is turned obliquely upwards. In the 
vicinity of the neck of the tooth, at the part corresponding to the vertex of 
the angle of the flexion, a distinct layer of enamel is presented, which resem- 
bles a flattened nodule and, when examined with a lens, seems to be sepa- 
rated from the enamel of the crown by a narrow zone of dentine. Natural 
size. 



132 



PATHOLOGY 



sur 




efface of the horizontally placed crowi 
and a marked mobility of the tooth and, 
indicate, Tvith a considerable degree of | 
of a flexion of the crown at an angle wit! 

Flexions of the roots are met with wear th< 
middle porti 

FIG. 52.* Fig. 53.f are f var iuUS '1 

degree are limited 

curvature; th< 

a step-like deyiati 

sharply defined bei 

(Fig. 52). F 1 ' ■ are 

the moat 
or zigzag (Fig. 53). 

The pulp-cavity is inclined in c 
of the crown, and the root-canal, in conformit; 
the roots, presents one or 
course. The continuity of I 
canals adapt themselves to the dil 

Axial torsions of th 
would be produced by I ,l * it* 

axis, so that the corresponding Burfi : - root 

do not lie in the same \ 
are met with only in teeth witi 
canine teeth, but also in bid 

to 180°, so that the facial Borfao varde 

the tongue, which, however. ■ re- 

taining its normal position. D time 

when the crown is just formed, may. 
be the cause of this phenomenon, while, dm 
expansion of the contracted space, t: 
develop in its normal position, 
the adaptation of the growth oi' tin 



* FiCt. 52.— Lateral view of n pr**e»U a 

sharply-defined flexion in the upper ! 

f Fig. 53. — Lateral view of an upper central preeeaU a 

double flexion towards the extremity < 



IRREGULARITi: JTRUCTURI. 103 

I for the lar • be the cause of the Bpiral 

twisting of roots which is met with. 

found apoo the bent crowns 
Mid roots, th« ibt that the direction th of 

the I oal influi ad in the fol- 

lowing mann< 

lor to the comple- 

quently, 

in wl • the 

middl 

. 

!ial intlu- 
— i i x i i - 

cells 1 1 

.1. ] 

tiall;. 

tttine 
and I • the 

th during . to such 

i t<» show 
the blow <t kick, sad the like, reallj 1 during the 

dly, how* tiente 

. whioh iikiv 1 

I in the 
in which tli< 

ilting 
M Dot i d intended in the 

I dental raptured ; in 

that lemonstri 

• ry. 



^ PATHOLOGY. 

which, however, is not the fact, for only a displacement of the 
dental tissues is met with. With this view of the - 

term " dilaceration " was not well chosen. 

In particular cases it is quite possible that contini 

of a tooth already cut upon one whose deyel< ; nterrup: 

or whose eruption is retarded, may 

placement of the coronal portion. The 

the present time these coronal flex! 

in teeth with single roots, cam. 

Flexions, at the commencement, in the middle or a1 

tremity of roots, evidently cannot 

external influences, but alwaya are in 

proportions of the space provided for then 

has been made. In man; want of 

the depth of the jaw and the length of 

flexion, as also may the retard.! 

compels the root, as its growth continues to turn off 

The facial or lingual wall. 

exert an influence, if the r 

strike against the wall. 

Flexions of the crown or neck ha\ 

to a united fracture of a tooth, and ha-. ich, 

as in the case described by II. IKr 

in proof of the occurrence of a fracture, 

is wanting in these cas 

b. Excessive Growth upon the ' 
irregularities coming under this head comprise chiefly the so- 
called enamel nodules, which are of small m :r in 
particular localities. Most of them are hemispheric 
growths, varying in size between dimim 
visible to the naked eye and tho£ to four millii 
diameter. They are located upon the oecl th with mul- 
tiple roots, at a slight distance from the boundary of tin 
or even upon or between the roots (Atlas. 
They have a white, polished, pearly, char, roui 

* Virchow's Archiv, Bd 

f C. Wedl, uber Knickungen und Drehnngen an d ■ und 

"Wurzeln der Ziihiie. Deutsche Viertelj. f. Z.. - 



IRREGULARITIES OF STRUCTURE. 135 

always are attached by the flat surface of the spherical segment, 
and, not infrequently, are united with the zone of the enamel 
by a narrow, spinous, sharp lamina. Heider and I, up to the 
present time, have observed well-formed enamel nodules only 
upon the molars of the upper jaw; and have never met with 
them upon teeth with single roots, but J. Tomes* gives an 
illustration of a case in which a large nodule of enamel is at- 
tached to the neck of a tooth with a single root. 

Occasionally ri ■ 1 are met with on the molars of 

the lower jaw, which, commencing at the boundary of the enamel 

on the neck of the tooth, are prolonged directly between the 
[interior and . but without forming nodular en- 

largemen 

Although tin-.' enamel aodnles arc occurrence still 

they are more common than i< BQpposed, Bince, "ii account of 
their unusually .-mall Bise, they are liable t" escape observation 
oil teeth which have just kracted and are covered with 

blood. It is obvious, that the hodulefl or ridges which are met 
with upon the molars are the results of localized continuations 

^\' the development of the enamel between the already devel- 
oped ba-al portions of the and are produced by the strip 
of the enamel organ which ha ted longer than the rest. 

If a section be made through an enamel nodule, it will be 
found that the enamel forme a thick layer upon a truncated 
of dentine (Atlas, Pig. 24 , In many nodules, cross-sec- 
tions of the enamel have a light color ami indicate a normal 
formation, while other- present an abundant deposit of pigment 
and an irregular arrangement of the prisms. The dentinal 
cone i> a direct prolongation from the dentine of the neck or 
. and contains dentinal canals which assume a regular ar- 
gement and a radiating course. Occasionally one or more 
empty spaces or cavities are met with wdiich are filled with mi- 
nute granules of calcareous stilts. 

With reference to their structure, the enamel nodules are to 
be regarded as lateral offshoots from the teeth, and are to be 
classed with the small dentiform excrescences wdiich are met 



in of Dental Surgery, Fig. 102. 



136 PATHOLOGY. 

■with, sometimes, upon the facial or lingual surfaces of the mo: 

especially those of the lower jaw. In many cases, particu: 

upon the upper milk molars, a cusp, covered with c; 

met with upon the lingual aspect of the neck, tl bich 

projects through the gum as if it 

to the false supposition that it is a nei 

emerging. 

An excess in the number of r> \ uncommon. 

numerary roots sometimes are Stunted in ti. 

they are completely developed, and occur either it m of 

lateral offshoots, or are produ 

roots, as is the case, particularly, with tl 

canines (Fig. 54), the upper bicu 
molars. 

It is very uncommon to find I 
upon the upper incisors and ca 
that is to say, upon the teetli which properly I 
ical roots (Fig. 55). A partial dii 
of a lower bicuspid is extremely 
consisting of lateral offshoots which i 
of the neck of the tooth and at 
length of the normal root, a; 
56 and 57). 

Roots which arise from a divisi 
words, cross-sections of them are circul 

Carabelli* observed an extreme! alI the 

bicuspids of a skull had three roots. T 
to possess three entirely distinct r 
same number upon those of the lowei 
deep depressions corresponding to thei 
especially, with three roots, arc f. 
cases the arrangement of th< 
roots of the molars, but they stand 
the teeth are more easily extr ; ^ 

^ 7^ L — karate. 
6), the divergence, in some case* 

* Anatomic d< - 



IRREGULARITIES OF STRUCTURE. 137 

traction of the teeth is accomplished very seldom without frac- 
ture of one of the ro< 

The occurrence of upper molars with five, and lower ones 

"6.* B7J Fl< 






with four root muted for bj a division of all the flattened 

root- Hi: to them. When the npper molars have four 

ilarly formed roots, the two flattened one* 
normally, are placed upon the outside, and the rounded ones, 
opposite the first, upon the inside. ( tently the Becond 

internal root is to be regarded rather as a supplemental one, 
that i . not the result of a division. 

Sometimes all the'lower molars have a third root which is 

roundish and located internally, towards the cavity of the 
mouth. I ■ molar a form similar to that of 

an upper and might, therefore, lead to a confounding of the two ; 

hut they may he distinguished by the fact that, in the lower 
molar, this third rout always arises from the inner surface of 

r Ine, with two root-canals 

in the divided r Lh, in which u - : pre- 

Natural 
. lower bicuspid with two broad roots; the latter are 

■ 1. and marked by a shallow gr« 

+ F >1 incisor with a short, conical supple- 

mental root, arising from the neck of the tooth. View of the labial surface. 
Natural li 

a much worn lower incisor, the lingual surface of 
which is bevelled, and upon its neck is located a short, conical, supplemental 
root. Natural I 

1| F be anterior surface of an upper bicuspid, with three 

distinct, slightly divergent ruots, and a normally formed crown. Natural 



138 PATHOLOGY. 

the base of the posterior root, and never from the middle por- 
tion of the neck of the tooth, as is the case with the roun 
root of the upper molar. Five entirely B . complet 

formed roots also are met with (A: 11 . in which CM 

the fifth, which is located upon the lingua] 6 wit 

of a division into three roots, but is B supplemental format: 
Both' upper and lower molars with more than five ro<>: 
also been observed, but such eases, it is evident, a; suit 

of the union of two molars. 

Under the head of excessive formation! i be con- 

sidered the unusually long or thi 
cases at least, the unusually 
finally the condyloid or nodulir 
with at the extremities of roots and I 
with hypertrophy of the cement. 

The length of the roots may \x ither aba 

relatively, i. e., in proportion to the depth and thickness of the 
jaw. In some cases, the second bic 

molars, are inserted to an unusual depth into the floor <-f 
antrum of Highmore, where they form lmmp-like prominei. 
and their extraction is likely to occasion q 

The three roots of the upper no 
excessive thickness and divei 2 Sometio - of 

the lower molars are very broad, and 

wide intervals. The extraction of the la: .ore 

difficult when the two adjacent teeth are -till present in 

It is not uncommon, in teeth with several 

development of the latter, in 

proportion, i. e., if the internal on 

outer ones are found to be stunted. 

Curves of all or of separate roots, which ly or 

relatively too long, occur in every conceiva! .. and a 

knowledge of them is of special int. 

since very slight deviations may be important 

way of extraction. For a long time, th< 

have devoted their attention to those cur 

the student will find in every manual of dentil 

and illustrations of such irregularities. 



IRREGULARITIES OF STRUCTURE. 139 

In rare cases, an incisor or canine root is curved posteriorly 
like a hook, or the radical extremities of upper and lower teeth 
with multiple roots converge in the shape of a bow which, some- 
times, forms a hook-like curve with a very decided bend (Atlas, 
Fig. 5). It is not uncommon for the extremities of each of the 
roots of wisdom teeth to present a strong curve, or for one of 
them or all of them blended together, to be bent like a hook 
(Atlas, Fig. 10). A quite uncommon irregularity is that in 
which one root 18 inserted between two others of the same tooth, 
as the thumb may be inserted between the index and middle 
fingers (Atlas, Pig, 1 l . 

The condyloid enlai ■_ upon the extremities of the roots, 

when tb- due to irregularities of formation, are to be 

ascribed to a hyperplastic process which takes place subsequent 

to the Completion of the root extremities. Of Such a character 

are the larger or Bmaller pisiform nodules which occupy the ex- 
tremities of the roots of the lower molars, and offer serious ob- 
stacles to the extraction of these teeth. Pisiform, condyloid 

enlargements are also not with, though very rarely, upon the 
extremities of the radical portions of the upper molar-. 

Among the ive formations in the dentine of the root, 

may be included the concentric dentinal formations (comp. den- 
tinal new formations), when they are located in the root-canal, 
near the apex, in very y< h. 

c. /> ', ■ Far I Hoofs. — Stunted 

Crowns are indicated by a diminished BUperficial area, and by 
the fact that the incif B, and CUSpS are less 

marked than is usually tie The enamel layer frequently is 

unusually thin, or form- an incomplete investment. The enamel 
cap is not everywhere smooth upon its outer surface, the pol- 
ished appearance peculiar to it and its transparency are, in a 
ire, lost. 

The four upper incisors, and, more frequently, the two lat- 
erals, sometimes present, upon their lingual surfaces, deep longi- 
tudinal grooves, which commence upon the roots and extend to 
the ends of the crowns. Upon the same surfaces of these teeth, 
it is not uncommon to find deep funnel-shaped depressions, or 
pits, surrounded by a fold-like elevation of the dental tissues. 



140 PATHOLOGY. 

To the practitioner, these grooves and pits have an irapor: 
signification, from the fact that they almost always are the - 
of the commencement of caries, though the latter very fn 
continues unrecognized until, finally, a bluish spot becomes i 
ceptible through the facial surface of the incisor. The er 
of the upper lateral incisors, also, ofu I 

incisive edges, in comparison with the well-d< a of 

the centrals. 

The crowns of the wisdom teeth, 
ones, are most frequently stunted in their 
upper wisdom teeth are duplicated, th< I, well-d< 

tooth is located in the dental range, wbil< 
one is located without the latter, upon 1 1 1 • 
tains scarcely two-thirds the size of the 

A diminution in the number of ro\ 
or complete blending together of the » 
In this manner, molars with two, and i 
upon which, however, the outlines 
have occurred normally, are more or 

When the three roots of the upper first molars ai 
they acquire a pyramidal form (Atlas, I 
cases, however, merely the extremiti 
roots are united, leaving a cleft-like interval, 
septum which necessarily must be removed wit! 
they are extracted. When the two external r 
in their entire length, a deep longitudinal _ 
along the external surface. Less frequently tl f 

the internal rounded root is united with th< 
When the extremities of the three 
the latter form an annular inclosnre around tl 
is inserted into the space intervening between : vi- 

olent, that such teeth cannot be extracted with 
the septa between the roots (Atlas ] 

The roots of the first lower molars, in manv cases, are unit 
hroughout into single, wedge-shaped roots, U, 
tion ^upon the outer and inner surfaces being indicated 

Coalescence of all the roots is met with m. B 



IRREGULARITIES OF STRUCTURE. 141 

the molars, since there is, usually, insufficient space for their 
normal development. Generally the roots are grooved through- 
out, indicating the parts where union has occurred. When the 
roots are completely united, which is more likely to occur with 
the upper wisdom teeth, tin- single root assumes a generally 
rounded appearance without any grooved markings, hut the ex- 
tremities may diverge and he Inserted in the jaw in the form 
of a trident, a condition which renders the extraction 
of such a tooth impossible without fracture of the 

In most cases the ( ie of the roots of a molar 

tooth is due partly t<> an unusually short or narrow 

maxillary arch. The union i^ formed by cement, which 
partially or entirely prevents the development of the 
partition walls of the en the roots. In certain in- 

stances, where tl separated by normal intervals ami 

are united by osseous e may assume the occurrence 

of a hyperplastic growth of cement from the dental sac. 

Frequently the / over the Burface of 

the coronal dentine ifl /// ; here and there, it i- de- 

fective, while the dentine, corresponding with the very distinct 

depressions and grooves upon the crowns, either is entirely un- 
protected <>r covered merely by a thin layer of enamel: on the 
other hand, the enamel is disproportionately thick in some Id- 
ealities ; for example, upon the dental OUSpS and eminences 

where the enamel occurs in the form of pediculated nod 

These appear rally by the greater num- 

ber of the teeth in a Bet and, not uncommonly, are hereditary. 

The permanent teeth are more frequently, and the milk teeth 
more rarely, the of these conditions; tli most 

conspicuous upon the Incisors, canines, and upper first molars, 
and are met with less frequently upon the lower first molars 

* Pig. 59 shows a stunted upper wisdom tooth from the right side. The 
masticating surface of the crown presents four blunt cusps. The roots are 
united into one cylindrical root, the extremity of which expands into three 
sh«»rt prongs, so that the tooth could not be separated entirely without break- 
way a portion of the alveolar pn ess. Natural size. (For the use of 
this specimen the author is indebted to Dr. Friedlowski.) 




242 PATHOLOGY. 

and bicuspids. The appearances presented by the malformed 
enamel in these cases are very characteristic. The surface of 
the enamel otherwise smooth, frequently is studded like a 
thimble, with numerous minute pits, some of which extend as far 
as the dentine ; sometimes it is traversed by transverse grooves 
which are bounded by ridges. In such instances, however, it is 
to be borne in mind that, although the external enamel layers 
present numerous pits, the internal layers 
fig. so* towards the dentine are invariably found to 

be smooth (Fig. 60). The thickened deposits 
of enamel occur upon the crenated incisive 
ed<*es of the incisors where fenestrated open- 
ings are met with which dip down as far as 
the dentine. Such teeth present a trans- 
versely grooved appearance. 
The cribriform, foraminated enamel upon the crowns of teeth 
with multiple roots is commonly limited to the masticating sur- 
faces, where, also, are located the papilliform thickened deposits 
of enamel. Not infrequently half the crown is destitute of 
enamel, only the portion adjacent to the neck of the tooth being 
covered. 

These defects in the formation of the enamel are generally 
included under the head of Atrophy in the manuals of dentistry, 
but this latter term is incorrectly applied, since defective forma- 
tion and atrophy are not identical. f 

* Fig. 60.— View of the interior of the enamel cap of a fully formed 
molar, from the jaw of a young person; its outer surface was studded with 
numerous depressions ; the cap was isolated by means of a fifty per cent, 
solution of sulphuric acid. The central portion of the grinding surface pre- 
sents a bifurcating fissure, to the right of which is a cavity the result of a 
suspension of the process of enamel formation at this point. Within the 
parietal wall is a groove (a), having the character of a sort of suture, where, 
likewise, the development of the enamel was interrupted for a certain period. 
Magnified two diameters. 

f These malformations are considered, without reason, by many practi- 
tioners, to be caused by hot drinks, sweet and sour articles of food, the use 
of acid preparations for the teeth, or other medicaments. They are referred, 
also, to a scrofulous diathesis by some who, however, adduce no plausible 
reasons for such an opinion. The truth is, that the only explanation which 
can be relied upon is to be attained upon anatomical grounds, and this way 



IRREGULARITIES OP STRUCTURE. 143 

It is the general opinion that teeth of this kind, with so many 
depressions upon their coronal surfaces giving to them a disa- 
greeable appearance, are very liable to be affected with caries at 
an early period, but they may, however, be preserved with 
proper care and cleanliness. 

Recently-cut molars are met with occasionally in which, 
whether they are the subjects of the enamel defects just de- 
scribed or not, the continuity of the enamel at the bottom of 
the grooves is interrupted, so that a fine probe may be inserted 
into the fissures which remain, as far as the dentine. In these 
cases, evidently, the development of the enamel has been defec- 
tive, since the enamel caps, which should cover the prominences 
of the teeth and form continuous layers in the grooves between 
them, present interruptions in their continuity. 

Defectively developed enamel is characterized histologically 
by the granular cloudiness of separate portions in which the 
structure is more or less altered and irregularly jagged borders 
are directed towards the normally developed enamel. With 
this condition, the enamel is capable of less resistance and easily 
crumbles. Very frequently, abundant deposits of dark-brown or 
blackish-brown pigment are observed, which render the structure 
of the enamel quite unrecognizable in places. 

was nuggested long ago by Bourdet (De Part du Dentiste, 1757, p. 79), who 
treated of such deformities under the name of Erosion, and considered them 
to be due to rachitis, scorbutus, low forms of fever, measles, variola, and, in 
general, to all those diseases in which the quality of the fluids is at fault. 
If, he says, the appearance of the disease is coincident with the commence- 
ment of ossification in the formation of the tooth, that portion which has 
not yet attained its proper consistence becomes principally affected and de- 
ficient in enamel ; as soon as the disease comes to an end and the fluids ac- 
quire a favorable condition, then the development of the remainder of the 
tooth is resumed in a regular manner, so that the enamel is white and smooth 
in the vicinity of the root, and abnormally formed towards the extremity of 
the coronal portion. The surgeon, Tenon, exhibited to Bourdet a series of 
jaws, by which it could be demonstrated that the erosion took place while 
the tooth was still within its capsule, and that the tooth, when it was ready 
for eruption, was less liable to erosion; those teeth, whose formation was 
most advanced, exhibited the least traces of the erosion towards the upper 
coronal surface, and the most notable evidences towards the neck of the 
tooth ; finally, those teeth whose crowns had emerged nearly to a level with 
the alveolar margins, and whose roots were still short, were barely affected. 



144 



PATHOLOGY 



Fig. 61* 




The depressions in the enamel present, externally, a wide 
opening, or, less frequently, are con- 
stricted, so as to form a sort of neck. 
The entire internal surface of the 
pression is covered with enamel, which 
may be of a normal character, with the 
exception of a variation in the arrange- 
ment of the prisms (F 

Where portions of the enamel, 
pecially its peripheral la 
tremely cloudy in appear I im- 

perfect formation hai 
granular calcareous 
The furrows upon 
grooved crowns give a terraced appearance to the 
seen in profile, though upon the surface towards the dentine the 
enamel is smooth, and, therefore, the portions 
the depressions are thinner than others A tin-. I 

The lamina of grooved enamel conform, in their dispof 

to the terrace-like outline of the 
exterior, thi 
tend, from one ten 
to another, in a 
parallel to the outer Burl 
when viewed in a longitudinal 
tion of the crown, t: 
system of concentric 
beneath each transverse de] 
sion, the system of laminre, which is more remote from the ii. 



Fig. 62.f 




* Fig. 61 shows a spherical excavation in the emu., -htped 

depression dips down from the surface to a considerable depth into the 
enamel, where it is connected with the spherical cavity by o 
neck. The wall, which appears intact in the tv. 
with normally-formed enamel prisms which, for the i 
transversely and obliquely. Magnified 260 diano 

f Fig. 62. — Imperfectly-developed enamel with extreme granular cl 
ness and numerous pits in its peripheral portions. In the 1 
mass of the deeper layers, enamel prisms, divided trai> 
(a) may still be recognized. Towards the masticating sur:. 



IRREGULARITIES OF STRUCTURE. 145 

edge or coronal apex, and is situated posteriorly in the horizontal 
plane, joins the adjacent system in front of it. The depressed 
portions commonly are the seat of extensive deposits of pigment. 

The continuity of the dentinal tissue of grooved teeth is always 
interrupted, here and there, by the interposition of large globular 
masses. The latter extend from the white zones, which are 
perceptible upon the exterior of the roots, in an oblique direc- 
tion towards the crown, where they are crowded together. The 
substance of the globular masses is transparent, while, on the 
contrary, the interglobular masses frequently have a brownish- 
yellow color, varying from this to a dark brown. The internal 
surface of the dentine not infrequently presents disordered sys- 
tems of dentinal canals and, in the vicinity of the extremity of 
the root, concentric dentinal formations. 

The cement of grooved teeth, likewise, presents some anomalies 
of development. The exterior is not everywhere even, and in 
some localities is so thin that the globular masses which are dis- 
posed in the superficial dentinal layer arc visible through it, at 
certain intervals, in the form of the white zones mentioned above. 
Towards the apex of the root flattened, tuberculated elevations 
of the cement are frequently met with. In the latter locality, 
also, irregular cavities are often found, which extend into the 
dentine. 

Teeth of such a character as have been described are due to 
disturbing causes which occur at intervals during the process of 
their formation, and prevent their uninterrupted development. 
In proof of the periodical occurrence of a disturbing cause may be 
cited the following: «, in reference to the enamel, that its laminae 
do not fall away uniformly from the incisive edge or coronal apex 
towards the neck and diminish in number, but breaks (Absiitze) 
are formed, each of which includes a system of layers ; b, the 
fact, that imperfectly-developed dentine, in the form of globular 
masses, is intercalated, and conforms in its disposition to that 

latter do not preserve their arrangement in rows, but lie scattered in a 
granular basis-substance, are grouped together here and there (6), present a 
shrivelled appearance, are indicated by a dark-bordered outline and, now 
and then, are transformed into a brownish-black mass of pigment. Magnified 
400 diameters. 

10 



146 PATHOLOGY. 

of- the layers forming the coronal and radical portions; hence 
may be inferred the occurrence of an interruption to the com- 
plete formation of the dentine; moreover, the irregular difl 
tion of the layers upon the internal surface of the dentine favors 
the view of an interruption to its symmetrical developmei 
in regard to the cement, the fact that its development | 
merely to the formation of a thin layer, and that the evidences 
of resorption in the cement as well as in the dentine occur at 
the radical extremity; consequently, the growth of the extremity 
of the root was not uniform. Another circumstance in fai 
the above view is, that these anomalies of formation art- 
found except in teeth whose development takes place at about 
the same period and, also, under nearly similar conditions, while 
teeth formed at a later period commonly are quite free from 
these irregularities.* 

* Hutchinson asserts that certain deviations in the foi h are 

valuable as diagnostic marks of the exist'' nstitutional 

syphilis, and he classes them with syphilitic interstitial keratitis. A 
(Deutsche Viertelj. f. Zahnheilk., 1862), in an extended criticU 
statements, observes that he cannot conceive, in the first place why the 
permanent canines and incisors only are affected, and why the milk 
were not also included by Hutchinson in his observations. Fr 
scriptions given of the deviations in form, that, namely, the U] 
incisors, after their eruption, are generally short, compr - 
the direction of the cutting edges, and are very thin ; that, 
a crescent-shaped piece becomes detached from the cutting 
shallow groove ; that the two teeth frequently converg :. other, 

and at times are wide apart; that they have a peculiar color, and a I 
quadrangular shape: all these are insufficient to afford positive grow 
pre-existence of syphilis, moreover, is not proved in main 
proofs therefore are still wanting of the occurrence of an hereditary syphilitic 
deformity of the teeth. 

[This is contrary to the opinion of many prominent medical men in this 
country and Europe. 

Mr. Jonathan Hutchinson, in summing up a large nunil 
terstitial keratitis in reference to the deformity of die tee( 
mic Hospital Reports, 1859, vol. ii, page 96) : « In those who h 
permanent set, the condition of the incisor teeth was very peer. 
form, color, and size. As diagnostic of hereditary syphilis, various 
harities are often presented by the others, especially the canii 
upper central incisors are the test teeth. When first cut. tl, - 
short, narrow from side to side at their edges, and very thii 



IRREGULARITIES OF STRUCTURE. 147 

d. Blending or Fusion, and Coalition or Concrescence of 
Adjacent Teeth. — Fusion (Verschrnelzung) of two adjacent 

a crescentic portion from their edge breaks away, leaving » broad, shallow, 
vertical notch, which is permanent for some years, but between twenty and 
thirty usually becomes obliterated by the premature wearing down of the 
tooth. The two teeth often converge, and sometimes they stand widely 
apart. In certain instances in which the notching is either wholly absent 
or but slightly marked, there is still a peculiar color, and a narrow square- 
ness of form, which are easily recognized by the practiced eye Since 

I have made it a rule always to look into the mouth, however, I have not 
met with a single example of well-characterized interstitial keratitis in 
which the teeth were of normal size and shape. Indeed there can be no 
doubt whatever as to the truth of the assertion that malformed upper incisors 
(permanent set) are all but invariably coincident with this disease. A few 
months' observation at any large ophthalmic institution will satisfy any one 
of this clinical fact." 

Dr. B. W. Richardson, in "The Medical History and Treatment of Dis- 
eases of the Teeth and the Adjacent Structures," London, I860, page 15, 
says: " In reference to the effects of the syphilitic poison#n the development 
of both the temporary and permanent teeth, the influence is undeniable, and 
I think it possible that there is scarcely any chronic disorder of the dental 
structure which is not influenced more or less by the effects of the syphilitic 
diathesis when present. But there seems also to be a special affection of the 
teeth due to the hereditary syphilitic disease." He then refers to Mr. 
Hutchinson's investigations as supporting his statement. 

Dr. Langdon Down, in a paper read before the " Odontological Society of 
Great Britain," "On the Relation of the Teeth and Mouth to Mental De- 
velopment" (Transactions, 1871, vol. 4), in speaking of this peculiar de- 
formity as occurring in the feeble-minded who have come under his observa- 
tion, says (page 17): " Very few have had syphilitic teeth ; but when 1 did 
discover them, I always had confirmatory evidence of the syphilitic history 
of the case, and the condition of the teeth was always as.-ociated with the 
chronic inflammation of the cornea to which Mr. Hutchinson has called 
attention." 

Dr. E. Magitot (in " Traite de la Carie Dentaire," 1867, page 67) says: 
"Syphilis, especially, produces disastrous effects upon the teeth, and we see 
that children affected with hereditary syphilis present small teeth, deformed, 
showing deep channellings ; and the enamel and dentine, imperfectly calci- 
fied, are covered with opaque spots, and remain permanently weak and 
friable." 

Henry W. "Williams, M.D., Professor of Ophthalmology in Harvard Uni- 
versity, a very eminent authority in this country, in " Kecent Advances in 
Ophthalmic Science," 1871, also confirms Mr. Hutchinson's observations. 
He says (page 56) : " The central incisors of the second dentition have a 
peculiar crescentic notch at their lower margins, and the lateral incisors and 
canines, as well as the molars, are often small, peg-shaped, and with tuber- 



148 PATHOLOGY. 

te'eth signifies an organic union between them, which takes place 
during their development. Coalition (Verwachsung) denotes 

culated prominences upon their surface. They are perhaps also irregularly 
set in the jaw, and of bad color, or prematurely decayed.'' 

These conditions have for some years been recognized by many dental 
practitioners. They must not be confounded with those which occur as the 
result of interrupted development, illustrated by the longitudinal grooving, 
with depressions or pits, in the enamel, caused by a perversion of nutrition 
induced by some of the non-specific infantile disk 

The appearance of syphilitic teeth is well shown by the accompanying 
plates, which were kindly furnished through the courtesy of Dr. "Williams. 
''Figures A and B show the condition of the teeth in a boy and gii 
about twelve and fourteen. In Figure C, from a girl of seventeen, the 
notched appearance has already become lessened by wear of the teeth." 

T. B. II. 







Fig. A. Fig. B. 



.'; - 



Albrecht considers it strange that only the permanent incisors and canines 
are affected, but Dr. Williams has shown that the molars also are 6ul 
a peculiar deformity. A close examination of Mr. Hutchinson's | 
that in a number of cases he does include the temporary teeth, gii 
instances of their early destruction or loss. This is also v 
servations of Dr. Williams, as well as by a cast in the Museum of the I 
Department of Harvard University. 

The reason that this condition of the temporary teeth has not 
nized more often is, probably, because the subjects of interstitial k 
general y do not come under the observation of the oculist until fr 
to eighteen years of age, when most of the temporary teeth are 1, - 
their p laces have been supplied by those of the permanent sot.-T. B II 1 

a H e d ( r"'- 0116 T^ elj - f Z " 1869) f ° Und ■ ™y * bund ** secretion of 
lha t An' v." I S6Ven yearS ° f aS6 ' affeCted * ith °o*S«^ hydro- 

milk teeth h *" ^f ^ ° f ' ^yish-yellow color, and Laller than 

of arie In he"" t WaS 7r nting *"** "**' «*"* ™? ™*™~ 
andTo ,1 T ? dGntine there W6re to * seen nu <™ <»»*> 

dispos LTw ?! ° m reS ° rpti0n ' imd iD tbe lMtter ~ » « 

diction to laminated arrangement, with numerous interglobular « 
Hohl considers that, in this case, there was an arrest of the develol 
he teeth, and a decalcification of the same upon their outer surf* 
to the absence of Leptothri. buccalis, he says caries could not lav c^L 



IRREGULARITIES OF STRUCTURE. 149 

an organic union by means of cement, which ensues after the 
completion of their development. The former arises from the 
coalescence of two adjacent germs, and must not be confounded 
with a twin-malformation, by which is understood a malforma- 
tion by duplication instead of a unification of normally exist- 
ing parts. In fusion, the tissues of the teeth which in other 
cases are separated by an interval pass from one to another 
without interruption, and the line of demarcation between the 
teeth is indicated by a more or less deep groove, similar to a 
raphe. 

Fusion is of two kinds, complete, when both the coronal and 
radical portions are united, and partial, when the union is 
limited to the crowns or the roots. The teeth may be united in 
their normal positions or at angles with each other, so that one 
tooth may preserve its normal position, while the other is twisted 
180°, with its lingual surface facing outwards. 

Blended crowns contain common pulp-cavities, blended roots, 
common or divided canals. Adhesions of adjacent teeth are 
confined to the roots, each of which contains a separate canal. 

Fusions belong to the category of rare occurrences, and 
affect both the milk and permanent teeth. They are particu- 
larly liable to be overlooked in the milk teeth, because, corres- 
ponding with the line of junction of the borders, there is a deep 
groove generally, which is likely to be mistaken for a complete 
division between the two teeth. Ileider mentions nineteen ex- 
amples of blended teeth, in his collection, eight of which belong 
to the milk, and eleven to the permanent teeth. The latter in- 
clude three cases of fusion of the upper left central with the 
lateral incisor, and one of the lower right central with the lat- 
eral incisor ; two cases, upon the right and left sides respectively, 
in which the upper second molar is blended with the wisdom 
tooth, and one instance similar to the latter, where the lower 
second molar and wisdom tooth are united; in one case, a lower 
right wisdom tooth is blended with a supernumerary wisdom 
tooth ; and finally, one presents a fusion between a lower wisdom 
and a so-called conical supernumerary tooth. (Two cases are 
not specified.) 

The blended milk teeth are limited chiefly to those of the 




150 PATHOLOGY. 

upper jaw; in three of the cases, the central is united with the 
lateral incisor; in four of them, the laterals are blended with 
canines, and, finally, in one case a lower milk canine is united 
with the first milk molar. 

A more precise anatomical examination of blended teeth with 
single roots, verifies the opinion which might be inferred before- 
hand, merely from a superficial inspection : a common pulp- 
cavity prolonged into each of the two crowns and a 
root-canal common to the two in some cases and, in 
others, divided (Fig. 63). Under the mi' 
cross-sections show an immediate transition of the 
dentine of one tooth into that of the other, a more 
circuitous course of the dentinal canals, as if they 
were bent, being perceptible only at the points cor- 
responding with the external groove. The enamel 
surrounds the coronal portion of the dentine in a very uniform 
manner and dips down to the bottom of the groove-, in 
to cover them throughout in the same way as upon multicuspid 
teeth (Atlas, Fig. 22). Hence it follows that it is impracticable 
to think of separating blended teeth at the groove by 
a file, since by such a procedure, the pulp-cavity would evi- 
dently be opened, the pulp injured, ami the existence of both 
teeth jeopardized. 

A complete fusion is not conceivable except it occurs in a 
dental sac, common to the two teeth, and since we know from 
the history of its development, that the formation of the dental 
sac belongs to an early period, therefore the fusion must I 
sarily be of early origin. We are able, howev< 
farther and say, that the fusion ensues contemporaneously with 
the first development of the enamel organ and dentinal '_ 
since we find that the dentine of one passes directly, i 
interruption, into that of the other tooth, and a conti, a 
enamel cap covers the united coronal portions of the dentine. 
As the cement of a single root is formed from a si: iform 



Fig 63.-Perpendicular section through two teeth ( th ,,d lat- 

eral milk incisors) which were blended together. View of tl 
half, showing the communication between the two pulp-cavities and tho 
union of the two root-canals at the extremity of the root. Natural size. 



IRREGULARITIES OF STRUCTURE. 151 

elongation of the dental sac, and a double root presupposes a 
double elongation of the dental sac, we may explain the occur- 
rence of the separation of the respective roots of crowns, which 
themselves are blended together, by the supposition of a division 
of the dentinal germ which forms the root. The raphe corres- 
ponds to the line of junction and fusion of the two germs. 

The possibility, that two separate crowns might be blended 
together by a resorption of the proximal surfaces, or that two 
perfectly formed and separate roots, each with its canal, might 
be united into one root with a common canal, is quite incon- 
ceivable. 

The fusion of the roots of adjacent teeth implies a union of 
the root-pulp of one tooth witli that of the adjacent one, in 
such a manner that ultimately by the junction of the root-canals 
of both teeth, usually at an acute angle, a single canal is pro- 
duced, terminating in the single root extremity. Such a union 
cannot take place except during the development of the roots 
of adjacent teeth, and it is impossible for it to be induced by a 
pathological process occurring after the complete formation of 
the roots of the two teeth. 

An example may serve to explain the preceding observations. 
A right upper jaw presents a fusion of the posterior external 
root of the first molar with the anterior external root of the 
second molar. The cavity of an abscess surrounds the two 
roots mentioned and the anterior external root of the first 
molar. The extremities of the roots involved lie exposed, while 
the facial wall of the jaw and the alveoli have been destroyed by 
suppuration. The crown and internal root of the first molar 
have been destroyed by caries. The proximal surfaces of the 
two first-named roots are completely united in their upper 
halves. Both teeth are movable together. The fusion of the 
two roots has occurred in such a manner that there is one root- 
canal common to both which corresponds more nearly to the di- 
rection of the anterior root of the second molar. The dentinal 
canals radiate from this canal in such a manner that there is no 
separation between the dentine of the two roots; the canal 
mentioned forms therefore the common centre of the two roots. 
The cement forms an uninterrupted investment to the latter. 



152 



PATHOLOGY. 



Fig. 64. 




except at a point upon the posterior root of the first molar 

where can be seen with the 
naked eve a fissured defect 
in the substance. Upon 
cross-section the fissure m 
be traced in the form of a 
raphe, into the common cen- 
tral canal (Fig. 64). 

Aa the blending of the 
roots in the way descril 
cannot be the result of an 
abscess of" the root-mem- 
brane, it must rather be- ad- 
mitted, although, as is well known, an interval of al 
years occurs between the eruption of the crowns of the first and 
second molars, that, nevertheless, a fnsion of these roots 
formation of a common root-canal took place during the pro- 
of their development. 

An anatomical examination alone can determine whetl 
case in hand is one of fusion. Therefore it admi not 

whether the cases cited as fusions (Atlas. Fig. 18 and 21 are 
really such, in the strictly correct sense of the * 

Coalition or concrescence of the roots oj 
place subsequent to the complete formation of the r» 
evidently, cannot occur without the previous resorption of the 
alveolar segments between the two roots which are united. In 
these cases, the question at once arises, why the cement layer 
of the root does not become adherent to the alveolus 1 I I 
frequently sought for such adhesions, but have never 
anything but mere contact with a very small portion of the al- 
veolus ; remove this fragment, which may easily and 
the root lying beneath it, presents a very smooth appearance, 
nor does a cross-section of the part in question indicate any ad- 
hesion. The explanation of this fact is to be sought for in the 
periosteum of the root, which, as before observed, is a product 



* Fig. 64 shows a fusion of the posterior external root of the upper first 
molar with the anterior external root of the second molar. M 
diameters. 



IRREGULARITIES OF STRUCTURE. 153 

of the submucous layer of the gum. The capillary, vascular 
system of the*root-membrane lies upon the surface towards the 
cement ; in that direction, therefore, the plastic elements for the 
new osseous layers are excrete.!, and it is impossible for them to 
be deposited in the opposite direction. 

When now resorption of the contiguous alveoli and the os- 
seous septa between the roots has occurred, which probably is 
promoted by the vessels of the septum, the periosteum of the 
two roots comes into contact and, from the continued deposition 
of new layers of cement, there results, finally, a coalition of the 
two roots. 

These adhesions of the roots of adjacent teeth are found, in 
most cases, towards the extremities, but they also occur in the 
middle portions. If the union takes place before one or the 
other tooth has advanced to its proper level in the dental range, 
then will its complete eruption be prevented (compare Reten- 
tion). This form of union seems to occur most frequently be- 
tween the upper second molars and wisdom teeth. The probable 
reason for this may be found in the fact that the roots of the 
upper molars, in consequence of their great divergence, are very 
liable to come into close relation with one or another root of the 
adjacent teeth, and, further, that the eruption of the wisdom 
teeth occurs comparatively slowly and, not infrequently, is at- 
tended with important obstructions, among which may be men- 
tioned an hypertrophy of the cement. Probably 
an irritation, applied to a larger or smaller por- fig. •;». 

tion of the root-membrane, is the predisposing 
cause, the result of which, a notable thickening 
of the cement, is illustrated in Figs. 48 and 49. 

In rare cases, the roots of the front teeth may 
be united in their middle portions in consequence 
of their very marked convergence (Fig. 6o). 



* Fig. 65 shows an organic adhesion, about five millimetres in extent, be- 
tween a permanent upper left central and the lateral incisor, at the middle 
portion of the contiguous surfaces of the roots. The two crowns, necks 
and radical extremities are entirely separated. The central incisor is in- 
clined laterally. The descent of the lateral to the level of the dental range 
was prevented in consequence of the adhesion Natural size. 




154 PATHOLOGY. 

Many persons suppose they have seen cases in which all the 
teeth, even upon the crowns, were adherent to one another, but 
such an occurrence is not conceivable, when it is considered that 
the teeth make their appearance singly, at different periods, and 
after intervals of years in some cases. Sommering and Blumen- 
thal, indeed, have shown that these supposed organic adl: 
are produced by the tartar of the teeth which cements tliem 
together; nevertheless this fable of travellers still has its be- 
lievers. 

These organic unions by fusion and by coalition, which have 
been mentioned, are of interest to the practitioner from the fact 
that, without making proper examination, he may commit the 
error of extracting not only the tooth he desires to remove, but 
also its neighbor at the same time. Of course, the latter evil 
cannot be avoided, when the extraction of the tooth at fault 
has become an imperative necessity. Still it is always an un- 
pleasant occurrence for the practitioner not to have n 
beforehand, the actual conditions, though, to be sure, this is a 
very difficult thing to do, in many cases, and sometime- - 
possible. Organic fusions of the crowns, however, may be 
recognized in all cases, by the fact that it is impossible to a 
rate them by the ordinary mechanical means (caoutchouc, 
wedges of wood, &c). When the union either by fusion i 
alition involves the roots, it cannot be recognized except 1 
attempt at extraction, when it will be seen that the adja 
tooth is moved at the same time with the one which is being 
extracted, a circumstance that does not escape the observation 
of a careful operator, who is enabled thereby to suspend the 
operation at an opportune moment, in cases in which there may 
be important reasons for the retention of the adjacent tooth, 
and the circumstances admit of a delay in the 'operation or 
allow it to be abandoned altogether. 

e. Malformations.- -These comprise irregularities of structure 
which mvolve the whole tooth or its greater portion, whereby 
its proper form is more or less lost and, sometimes, it is eh: 
into a shapeless mass. Collections of such teeth' form a series 
of most remarkable deformities which are not merely of histo- 
genetic interest, but whieh it is necessary for a practitioner to 



IRREGULARITIES OF STRUCTURE. 155 

be able to recognize, since, in very rare cases, it devolves upon 
him to decide whether certain formations are dental structures. 
In some respects, under this head should also be classed super- 
numerary teeth which have been considered in connection with 
excess in the number of teeth, in accordance with common prac- 
tice : these are distinguished not so much by an irregularity of 
structure, or of the relations of the arrangement of the dental 
tissues, but rather by deviation in their external conformation, 
so that they cannot properly be classified with any of the dif- 
ferent kinds of teeth. 

The malformations of teeth have their analogies in other 
organs ; in extremely rare cases they involve the wliole set of 
teeth; but generally are limited to separate ones. Heider ob- 
served, in one instance, a very remarkable malformed set of 
teeth. In the place of the upper and lower incisors, canines, 
and bicuspids, there were throughout roundish, large, pisiform, 
hard formations covered with fine white enamel, which were 
flattened a little only at the points of contact between the upper 
and under rows. 

The malformations may also occur primarily in the soft parts 
of the developing tooth, whereby the development of the hard 
tissues becomes arrested.* 

Their development is still a matter of uncertainty in many 
respects, and we are able merely to infer it from the malfor- 
mation already produced ; the opportunity of tracing it anatom- 
ically, in its different stages, has been afforded only in extremely 
rare cases. 



* All deformities of this description have been distinguished of late years 
as odontomata, and Virchow (Krankhafte Geschwiilste, Bd. ii) divides them 
into two classes, namely, those which are a product of the developmental 
period of the teeth, and the so-called odontomata interna, which make their 
appearance after the period of development. Broca (Gaz. Hebd. de Med. et 
Chir., 1868) assumes four periods of their formation, and divides them into 
odontomata embryoplastica, odontoplastica, coronaria, and radicularia. The 
cases under 3 (p. 158) would be classed with his odontomes odontoplastiques t 
and Broca states, that the latter are to be considered merely as deformi- 
ties resulting from a disease of the pulp. The absence of histological inves- 
tigations in his account and, especially, his disregard of the history of the 
development of the teeth, afford an explanation of such a misunderstanding. 



156 PATHOLOGY. 

The malformations are confined, in most cases, to the coronal 
portions. Upon these, then, there is found an arrest of develop- 
ment at a stage prior to that of their complete formation ; 
pathological processes, however, always enter into both the 
enamel and dentinal formation, concerning the predisposing 
causes of which we know nothing. The more frequent occur- 
rence of malformations of the second and third molars may pos- 
sibly indicate that interruptions in the growth of the bone in 
length, a dislocated wisdom tooth, or a deficiency of space in 
general, exercise an influence upon the coronal formation, which 
is productive of disease. The enamel organ, excited to too 
great productive activity, or impeded in its normal productivity 
or in the direction of its growth, acquires manifold irregular 
sinuosities, the calcification of the enamel cells, which probably 
have never attained to maturity, is interrupted, and the forma- 
tion of enamel prisms does not occur everywhere ; homogeneous 
resisting masses of a yellowish color and sometimes of a granular 
structure occur, which are all the more to be regarded as rudi- 
mentary enamel, since, here and there, they present indie 
of enamel prisms. The enamel cap, which not infrequently has 
a cribriform appearance, loses its proper form more or 
Sometimes, also, an unusually protracted persistence of the 
enamel organ, especially when associated with abnormal devel- 
opment of the dentine, may have a share in producing the 
irregular enamel formation. 

Contemporaneous with that of the enamel occurs a deviation 
from the normal development of the dentine. The dentinal 
germ acquires multifarious papillary excrescences containing 
bloodvessels. The latter become obliterated as the formation 
of dentine continues; the connective tissue, in which they lie", 
becomes calcified; there remains, consequently, a system of 
irregular calcified tubes and cavities surrounded by dentine. 
The development of the dentine, in many parts, is arrested at 
the stage of the formation of globules with interglobular s^ 
Frequently the globules are met with in the form of Ion- streaks 
in the midst of well-developed dentine, and also extendir. 
tween the enamel layers. When there are multiple contiguous 
dentinal formations within the pulp of the malformed tooth, the 



IRREGULARITIES OF STRUCTURE. 157 

cavity of the latter becomes reduced, ultimately, to a cleft-like 
gap containing, usually, the calcified remains of the pulp. The 
canals, with their distinct, smooth walls, within the dentine, give 
to the latter the appearance of vaso-dentine, and not infrequently 
also of osteo-dentine. 

The development of the roots is impossible when sufficient 
space is not reserved for them in the jaw, or their growth is in- 
terfered with by a developing crown which lies behind them. 
Under the latter circumstances it is evident that the develop- 
ment of the cement is arrested at an early stage, or, if it reaches 
a more advanced stage, the cement terminates the malformed 
tooth in the form of a stunted root. 

Our knowledge in regard to the malformations of the teeth is 
still too limited to allow of a systematic division of them. The 
following classification, based upon general appearances, requires, 
therefore, still further additions in order to make it complete. 

1. Dwarfish Malformation of the Crowns and Roots. — 
Dwarfish growth affects the wisdom teeth most frequently, and 
occurs by itself, unaccompanied by any other deformity (vide 
Fig. 59). In a dwarfish growth both the stunted crown and the 
roots are malformed (Atlas, Figs. 30, 31, 32); in place of the 
pulp-cavities are found fissure-like spaces; the dentine presents 
evidences of various interruptions in its development, which are 
indicated by numerous aggregations of globular masses towards 
the enamel boundary and, indeed, extending even into the 
enamel in wide, sharply-defined canals. It is probable, there- 
fore, that, at the time of the primary formation of the enamel 
cap, interruptions in its continuity were produced corresponding 
with the imperfectly-developed portions of the dentinal germ, 
and the structureless lining membrane of the canals in the 
enamel (Atlas, Fig. 32) may be regarded as possibly the re- 
mains of the stunted dentinal germ. Osteo-dentine also is met 
with, interposed in the dentine, and may extend even as far as 
the enamel boundary and, here and there, is invested by a nar- 
row border of enamel. In such cases the radical portion of the 
pulp is not developed. J. Tomes* observed a rare case which 

* Op. cit., p. 229. 



158 PATHOLOGY. 

belongs to this class, of an upper central incisor, irregular in 
shape, and only one-fourth the size of the corresponding tooth. 
2. General monstrous development of the Crown, with weU- 
developed Boots, is illustrated in the Atlas, Fig. 9. The exterior 
of the crown presented such colossal proportions, in this case, 
that Heider and I were led to question as to its being a human 
tooth. The structure of the root portion, however, corresponds 
so exactly with that of a human upper molar, that we were de- 
cided in pronouncing it such. The roots, indeed, are large ; 
but it is a frequent occurrence to meet with roots as large as 
these in association with normal crowns. The most prominent 
points to be observed in the crown are, the uniform longitudinal 
folds of enamel, and the thick layer of osseou- which 

everywhere invests the enamel folds and is in immediate con- 
nection with the cement of the root. It is quite remarkable 
that a crown three centimetres in length and two and a half 
centimetres in breadth should, on the whole, present such s 
evidences of interrupted development, and, besides, that the 
structure of the roots should remain normal. The dental sac 
must have required for itself an extremely large space, and it is 
evident that the thick osseous layer still continued its develop- 
ment even after the coronal eminences emerged. Special con- 
ditions also must have existed to prevent suppuration and 
necrosis subsequent to the complete formation of the crown. 

3. General Malformation of the Crown of a M lar with un- 
developed Roots, in association with the deeply imbed \ 
of a Wisdom Tooth. — Few cases of this description have 
recorded up to the present time, since formerly no attenti- 
given to the anatomical examination of them. They com 
with one another, in so far that the surface of the crowns, which 
is occupied by numerous warty excrescences, has a convex out- 
line, while the portion turned towards the crown of the wisdom 
tooth presents an impression as it were of the latter which not 
infrequently is bounded by a rim of enamel: they are conn 
principally, of vaso-dentine cavities containing, mostly, calca- 
reous salts, and an irregular, sometimes notably interrupted, 
formation of enamel folds. The pulp-cavity is apparent, but in 
a rudimentary condition of narrow cleft-like channels. 



IRREGULARITIES OF STRUCTURE. 159 

very great clinical interest which attaches to these cases leads 
me to enter more into particulars concerning them. 

A case in point occurred in the practice of Dr. Jarisch, Sr.* 
A female silk-weaver, twenty-five years of age, of a weakly 
habit of body, reported the appearance during the night of a 
tumor upon the side of the angle of the right lower jaw. Later, 
severe pains were felt, and a swelling was perceived in the region 
of the right wisdom tooth, which led to the opinion that the 
eruption of the tooth was in progress. This condition continued 
two to three months, and then, with symptoms of trismus, a 
collection of pus was formed, which escaped upon the side of the 
neck through three fistulous openings. Fifteen months after 
the first appearance of the tumor, the patient came under the 
observation of Dr. Jarisch. At this time there was a very ex- 
tensive inflammation of the lower jaw and its vicinity, with pro- 
fuse suppuration ; the bone was notably enlarged. Emollients 
were ordered. After a few days, the swelling had diminished, 
and upon the right side, in the region of the wisdom tooth, there 
was found a body, the size of the end of the little finger ; it was 
pale, covered with pus, and when tapped upon, gave a sound 
like enamel. After the inflammation had subsided still more, 
this body was removed by the forceps, with very little difficulty. 
The parts having been cleansed, the wisdom tooth was brought 
into view at the bottom of the cavity; the probe could be passed 
entirely around it, and its crown exactly fitted into the base of 
the solid formation which was extracted. f 

The malformed tooth, described in the Atlas, Figs. 34-38, 
inclusive, for the report of which we are indebted to Prof. 
Strasky of Lemberg, was removed from the jaw of a strong 
man, twenty odd years of age, who presented a tumor of the 
cheek on the right side, which lasted for several weeks and was 
accompanied by difficult deglutition, trismus, and pain. Strasky 
made an examination of the mouth with great difficulty, as the 
jaws could not be separated more than an inch, and found that 
the gum upon the affected side, from the first bicuspid poste- 

* Reported by C. Wedl in the Zeitschr. der Gesellschaft der Wiener 
Aerzte, 1851. 

f For the anatomical description of this solid body, vide Atlas, Fig. 39. 



160 PATHOLOGY. 

riorly, was considerably swollen, reddened, sensitive, and, on 
pressure in direction of the angle of the jaw, it yielded some 
pus. All the wisdom teeth were wanting. Examination with 
the probe showed that the right second molar, merely the rough 
masticating surface of which had emerged, was loosened. The 
diagnosis was made of an impeded eruption of the wisdom tooth, 
and the loosened malformed tooth removed, a difficult operation, 
with so slight a separation of the jaws, and the only thing to be 
done was to turn the tooth over to the outside. A considerable 
amount of pus mixed with blood escaped after the extraction of 
the tooth. The tumor diminished rapidly within eight days, 
and after a few months the eruption of the normally-formed 
wisdom tooth occurred. 

The latter case, in its clinical history, is analogous to the 
former; the type of the deformity also, in the two cases, is 
similar; in structure, the latter tooth is distinguished by the 
fact that the enamel in its numerous folds is of a much higher 
grade of development, and that the osseous substance between 
the enamel and dentine and in isolated spots, is perfectlv devel- 
oped ; consequently, the three hard dental tissues are more 
perfectly developed in this case than in the former. 

A very instructive case occurred in the practice of Dr. Stein- 
beiiger,* where it was difficult and particularly important, to 
form a correct diagnosis, because upon this depended the decision 
of the question, whether to remove a portion of the jaw or to 
separate the morbid formation from the cavity in which it was 
imbedded. The patient, a girl, eighteen years of age. presented 
quite a large tumor upon the right lower jaw, extending from 
the coronoid process as far as the second bicuspid tooth, and 
two inches in depth. The protrusion of the maxillary wall was 
much greater upon the outside than upon the inside. The whole 
tumor was covered by considerably thickened mucous membrane. 
Separation of the jaws was impeded and painful. These inflam- 
matory symptoms continued eight days, and resembled closely 
those attending the eruption of a wisdom tooth. Steinbereer 



L,: h ; e t:^ e M: eines ^- za ^ ^ *■ ***- **«**- 



resschr. f. Zahnh., 1869 






IRREGULARITIES OF STRUCTURE. 161 

was confident of the existence of the latter, but was not a little 
surprised to find, on examination of the jaw, that all the molars 
on this side were absent. According to the statement of the 
patient, the first molar had been extracted several years previous 
to that time, while the two others had never made their appear- 
ance. As the molar upon the right side of the upper jaw caused 
pain by pressure upon the swollen gum which was spread over 
the tumor, the molars and bicuspids on the left side of the lower 
jaw were capped with hard rubber, which was to be worn day 
and night. 

After a few days, the pain had quite subsided, and the inflam- 
matory symptoms almost disappeared, subsequent to the forma- 
tion and evacuation of an abscess, but the lower jaw continued to 
be considerably thickened. After three weeks had elapsed, by 
removing the gum which covered the tumor, a yellowish-white, 
solid body, with a rough surface, imbedded within the jaw, was 
detected by means of a probe. After this Steinberger was as- 
sured that the case was not one of a cyst in the bone, but of a 
malformation of a tooth. In order, however, to render the 
diagnosis still more positive, he trephined the body, and gave 
me a fragment, about two millimetres in diameter, for examina- 
tion, and this showed the essential elements of irregularly-devel- 
oped dentine.* All doubts being thus removed, Dr. Weinlech- 
ner decided to undertake the removal of the malformed monstrous 
tooth from the mouth. As only a small portion of the malfor- 
mation was exposed to view, the greater part of it being over- 
lapped by the alveolar plates of the jaw, a simple operation for 
the extraction was out of the question ; it was evident, that a 
portion of the jaw must be removed with the chisel. Weinlechner, 
in the first place, detached the gum from the alveolar margins 
with a scalpel, and endeavored to separate the tumor from the 
alveolar borders by means of an elevator. Then, with a wide- 
expanding forceps, he tried to seize the mass, but without suc- 
cess, because the solid formation was overlapped upon the outside 
by the edge of the bone. Thereupon he inserted a Serres' 
screw into the hole previously made by the trephine, by which 
means he was enabled to move the solid body, after he had cut 

* Deutsche Vierteljahrssch. f Zhlk., 1869. 
11 



162 PATHOLOGY. 

away a portion of the external alveolar wall. Having enlarged 
the entrance to the cavity in the vicinity of the coronoid process, 
by means of chisel and hammer, he introduced the chisel between 
the external bony wall and the solid body, and by using the 
former as a lever, loosened the tumor and displaced it internally. 
At the bottom of the cavity the crown of the growing wisdom 
tooth was seen, so that the diagnosis was confirmed by the 
operation, and the patient's jaw preserved, though in all prob- 
ability it would have been sacrificed had she applied to a surgeon 
instead of a dentist. Such is the account given by Steinberger. 
The deformed tooth is about the size and shape of a chestnut. 
The long diameter, from before backward^ measures 29, the 
height 19, the breadth, from the outside to the inside. 18 mil- 
limetres. Its weight, when moist, is 12.37 grammes, the color a 
clear, pale yellow, the consistence apparently firm ; when tapped 
with a knife-blade, it yields a clear tone, of a high pitch, like 
that given by a tooth. The upper surface is convex, and occu- 
pied by numerous masses of tuberculated, small, resisting, 
yellowish, globular excrescences. The lateral surfaces are 
curved and traversed bv grooves. The inferior 

Fig. 66.* r . , 

surtace presents a cavity with a quadrangular 
border; this is situated somewhat to the out- 
side, and obliquely ; is three to four millimetres 
in depth, and, in size and shape, corresponds 
with that of the crown of a lower molar (Fig. 
66). That portion of the surface of the cavity 
which faces outwards has a smooth appearance, 
while that portion which is directed in war 
studded with several quite large and many small excrescences 
similar to enamel nodules. 

Delicate, firmly-adherent fringes are attached to the entire 
periphery of the malformation, excepting to the cavity in its 
under surface. In several places, short strips of a thin mem- 
brane, which is intimately united with the superficial layer of 




Pig. 66—Malformed crown of the second lower molar on the right side. 
I he cavity was produced by the crown of the wisdom tooth which 
beneath >t Natural size. (For the use of this specimen the author is in- 
debted to Dr. Steinberger.) 



IRREGULARITIES OF STRUCTURE. 



163 



the solid body, spread over the peripheral warty excrescences. 
Interlacing bundles of wavy connective tissue form the principal 
constituent of the fringed membranous investment, which con- 
tains within its tissue collapsed capillary bloodvessels with 
oblong nuclei longitudinally disposed, the larger presenting also 
nuclei running in transverse directions. Besides these, sharply- 
defined, bifurcating, here and there closed tubes, lined with a 
layer of cells like epithelium, are also met with. In a few 
places, flattened papilliform excrescences are to be seen, which 
present upon their external surfaces rows of cells terminating 
in pointed extremities, and suggestive of dentinal cells. Finally, 
in many localities,, tolerably large flattened cells, with large 
nuclei, occur, in regard to which, also, it is still undetermined, 
whether they belong to the rudimentary gelatinous layer of the 
enamel organ {Organ adamantines). 

Polished sections of the tooth, made by sawing through it in 
its longitudinal axis, show no pulp-cavity, but merely a number 
of hard formations which inclose a central mass, visible even to 
the naked eye, but more clearly appreciated by means of a lens; 
these hard formations penetrate from the surface into the sub- 
stance of the tooth, are well defined, and terminate like a shut 
sac ; in cross-section, they present a variety of shapes between 
circular and oval, and are mutually adapted, one to another. 

Thin, ground sections afford a more definite idea of the textural 
relations (Fig. 67). The three 
dental tissues are apparent, 
though their distribution is quite 
abnormal. The principal mass 
is composed of dentine, the ca- 
nals of which, in varying num- 
bers, radiate from cavities (the 
central masses of the above- 
mentioned mutually adapted 
hard formations), and, after 



Fio. 67.* 




* Fig. 67. — Segment of a transverse section from the same malformed 
crown. The dark streaks extending in different directions are the remains 
of the pulp around which the systems of dentinal canals are grouped. 
3Iagnitied 10 diameters. 



164: PATHOLOGY. 

traversing a longer or shorter distance, become lost to view in 
the peripheral, abundant, globular masses which invest the 
system of canals, or more often in the interglobular spaces, after 
numerous dichotomous divisions. Here and there, the neighbor- 
ing systems of dentinal canals unite and decussate with 
other. The arrangement and course of these canals are quite 
normal, in some localities, while, in others, they are fewer in 
number, assume tortuous courses in great variety, and d< 
present the bushy appearance peculiar to them. The abundant 
globular masses not infrequently penetrate to a considerabl 
tance between the dentinal layers. 

The above-mentioned irregular cavities of various dimene 
contain opaque, amorphous, calcareous salts, and are the more 
to be regarded as the remains of the pulp-cavity, since bl 
stained portions also are met with. Besides tlie>e cavities, the 
dentine also contains canals, filled with hyaline, calca 
grains which, here and there, have the appearance of 
still imbued with fresh blood; therefore a formation of 
dentine likewise occurred, to which, here and there, ther 
a continued supply of blood. 

In the vicinity of the inferior excavated surface, the enamel 
presents very distinct nodular projections, while, laterally 
it is elevated into an irregular narrow ridge. Irregular conical 
processes of enamel are prolonged, in many places, into the 
dentinal layers. Generally speaking, completely developed 
enamel, with longitudinally, obliquely and transversely divided 
prisms, is not of frequent occurrence; but it is, for the most 
part, rudimentary in character, composed merely of diff 
yellowish and dark-brown, resisting masses containing tra 
prisms. 

The cement is more or less distinct upon the upper convex- 
surface of the malformation, of unequal thickness, and is marked, 
here and there, with indentations, the results of the proo 
resorption. True bone-corpuscles, with multiradiatin- eanali- 
cuh, and a striated intercorpuscular substance, are ; 
in many localities, while in others the cement is retarded in its 
development. Finally, there remains to be noticed, the occur- 
rence of one or more groups of well-marked bone-corpuscles 



IRREGULARITIES OF STRUCTURE. 165 

which are interpolated in the neighborhood of the globular sub- 
stances in the deeper layers of the malformation, care being 
requisite in order to avoid confounding interglobular spaces 
filled with calcareous salts, with bone-corpuscles. 

The origin of this monstrous tooth can only be conjectured. 
This much, however, may with reason be admitted ; that the in- 
terlacing of the systems of dentinal canals is explained by the 
existence of numerous new formations of dentine (odontomes), 
extending in various directions into the pulp; for the same 
reason, also, the pulp-cavity is represented merely by cleft-like 
gaps. From the abundant and very irregular folding of the 
enamel organ, the conical prolongations, extending inwards, re- 
sulted. As before observed, I agree with J. Tomes, in consid- 
ering Xasmyth's membrane to be a continuation of the cement 
layer and, also, a rudimentary osseous tissue, so that to my 
mind, the occurrence of an osseous substance, in an advanced 
stage of development, is readily explained. 

There can scarcely, indeed, be any doubt but that, in this 
case which, clinically, was carefully studied, a dislocation of the 
germ of the wisdom tooth occurred during the growth of the 
second molar, in consequence of a deficiency of space, whereby 
the former, instead of assuming a position behind, became lo- 
cated beneath the second molar ; the subsequent formation of 
its crown prevented the development of the radical portion of 
the molar tooth and, in all probability, was the general exciting 
cause of the whole mischief. In the imperfectly formed crown 
of the second molar, both the dentine and enamel, as well as 
the cement, became developed in abnormal directions, and the 
growth of the separate tissues in some parts was excessive and 
in others defective. The fact, that the growth of the malformed 
tooth continued beyond the ordinary period until its eruption, is 
confirmed by the demonstrable, well-preserved bloodvessels con- 
tained in the connective tissue fringes of the exterior, and that 
the deformed mass was penetrated by the wisdom tooth lying 
beneath it, is indicated by the cavity presented by the under 
surface of the deformed tooth, which is a cast of the crown of 
the wisdom tooth. 



100 PATHOLOGY. 

' In view of the great interest of his case, Dr. Steinberger, at 
intervals of several months, prepared three plaster casts of the 
surface of the lower jaw, and kindly loaned me the models. 
The illustrations given in Figs. 68 and 69 correspond with the 

FI( ,68.* FlG - 69 - t 





first two periods and show the variation in the cavity, which 
was occupied by the malformed tooth, and the change in the 
position of the wisdom tooth. 

If a horizontal plane he projected posteriorly from the masti- 
cating surface of the second bicuspid tooth, and the distance 
from the posterior coronal border of the latter to the anterior 
border of the wisdom tooth, in the visual plane, in other words, 
if their distance from each other upon the longitudinal plane, 
at the first period, be measured and compared with the distance 
at the second period, it will be found, that the longitudinal dis- 



* Fig. 68. — Plaster cast of a right half of a lower jaw, showing, posterior 
to the alveolar cicatrix of the first molar, a cavity from which the malformed 
second molar was removed by operative means. At the bottom of the cavity 
may be seen the wisdom tooth displaced to one side. Th* 1 cast was taken 
soon after the operation. Two-thirds natural size. 

f Fig. 69. — Plaster cast of the same segment of the right lower jaw, 
taken several months after the removal of the malformed tooth. The di- 
mensions of the cavity have diminished, and the crown of the wisdom tooth 
has reached a higher level and moved towards the median line. Two-thirds 
natural size. (For the use of both casts the author is indebted to Dr. Stein- 
berger.) 



IRREGULARITIES OF STRUCTURE. 167 

tance between the two teeth = sixteen millimetres has remained 
unchanged, but that on the other hand, the masticating surface 
of the wisdom tooth has been raised about nine millimetres and 
lies only three millimetres below the level of the second bi- 
cuspid. The wisdom tooth, however, has also been displaced 
from the outside inwards, so that it is but a few millimetres to 
the outside of its normal position. The dimensions of the cavity 
present a considerable diminution in the later period ; the lon- 
gitudinal diameter being about twelve millimetres, the transverse 
about six millimetres ; the approximation of the facial to the 
lingual maxillary wall has been brought about by the process of 
cicatrization, the contraction of the cavity being analogous to 
that of the alveoli subsequent to the extraction of teeth. 

J. Tomes* reports a very similar case. The deformed molar 
of the lower jaw, likewise located over the wisdom tooth, was 
several times larger than the latter, the development of which 
was retarded. The nature of the case w T as not rightly under- 
stood, consequently a portion of the jaw was removed. 

Analogous malformations are met with in animals, and have 
been observed in the horse by Etienne Geoffroy St. Hilaire, 
and Rousseau. I am indebted to Prof. Bruckmiiller, of the 
Vienna Veterinary Institute, for an extremely rare example of 
a malformed left molar from a horse. The colossal tooth at- 
tained about the size of an orange and, evidently, was located 
within the dental range, for upon the anterior and posterior sur- 
faces are to be seen, in directions oblique to each other, the 
abraded surfaces produced by friction with the contiguous sur- 
faces of the adjacent molars. The monstrous formation pre- 
sents one surface, convex, rough, studded with numerous denta- 
tions, and another, excavated, and polished jn appearance, 
corresponding to the masticating surface. The latter presents 
a substance composed of enamel and dentine, which is trans- 
versely disposed from the outside to the inside, one to five mil- 
limetres in width, sharply defined, and divides the excavation 
into two unequal portions. 

The remainder of the tooth is composed of finely porous osse- 

* Op. cit. } p. 224. 



168 



PATHOLOGY. 



ous substance and dentine. 



The enamel extends from the masti- 
cating surface (Fig. 70), 
into the substance of the 
tooth, where it forms nar- 
row zigzag folds, which 
are accompanied by the 
dentine. Towards the 
lower portion, the periph- 
eral cement peneti 
to various depths. The 
pulp-cavity is wanting, 
its upper portion being 
filled with osteo-dentinal 
masses, which distend the 
walls of the cavity. 

4. J. Tomesf also mentions jiartial deformities of t 

in the form of excrescences. An outgrowth of this kind came 
under his observation, upon the anterior surface of an upper 
central incisor, and consisted of imperfectly developed and ir- 
regularly arranged dental tissues. He also states, that 
described by Salter in the "Pathological Transactions," under 
the title of a "Warty Tooth," comes under this head. 

5. Fissures. — During the development of the tooth, it hap- 




* Fig. 70 shows a carious, malformed left molar from a horse. (For this 
specimen the author is indebted to Prof. Bruckmul. 
The smooth, masticating surface (a) has a polished appearai 
cavated and divided into two unequal portions by a substance comp 
enamel and dentine, which extends from below upwards. One of the two 
abraded surfaces, produced by friction with the anterior and posterior adja- 
cent teeth, is visible, (b). The osseous substance is, comparatively, mor- 
dant than the other tissues, and forms the mass lying upon either side, like 
a kernel in a shell, in which mass are imbedded striated markings of dentine, 
(c) At the outer part of the substance forming the shell, osseous ti-sue 
(d, d) is met with, which is united with irregular folds of enamel | e), and in- 
ternally to the latter, with dentine. Confused masses of dentinal tissu 
however, which are traversed by canals, are met with, also, in iinr. 
connection with the cement. The occurrence of caries upon the superficial 
portion of the grooved masticating surface has left jagged, discolored cav- 
ities. Two-thirds natural size. 

f Op. cit., p. 227. 



IRREGULARITIES OF STRUCTURE. 169 

pens, sometimes, that the continuity of the enamel cap becomes 
interrupted, and the dentine appears to penetrate into the cleft- 
like gaps of the enamel. The dentine, also, is developed beyond 
its normal limits in many places, and hence another source of 
cleft-formations. The fissures in the enamel are sharply cut and 
filled with dentinal globules (Atlas, Fig. 32). In most cases, 
the growth of the dentine does not extend into the fissures, 
and we find merely cleft-like gaps in the substance of the en- 
amel cap. 

The dentine may, however, attain a higher grade of develop- 
ment in the fissures, as is illustrated by Fig. 33 in the Atlas, 
where the crown and root of a wisdom tooth present an appear- 
ance as if they had been divided by a longitudinal section, and 
a flattened plate of dentine had been introduced into the fissure, 
where it had continued to grow and become firmly adherent. 
Fissures in the roots are due to defective union of the two rad- 
ical halves. A fissure in the neck extending into the root- 
canal, and surrounded by a layer of enamel which extends 
perhaps to the bottom of the cleft (Atlas, Fig. 27), sometimes 
occurs, though it is extremely rare. 

6. Monstrous outgroivth of Dentine and Cement [osteo-odon- 
toma) upon the Root. — Rare tumors of this description are de- 
veloped, during the formation of the roots, from a circumscribed 
portion of the radical pulp. The hard tissues of the tumor 
comprise bone and dentine, but, as the crown is not involved, 
enamel is not found (Atlas, Figs. 28 and 20). The cortical 
tissue of the tumor is composed of cement, beneath which is 
found a comparatively thin, but normally formed layer of den- 
tine ; immediately internal to the latter expands the abundantly 
vascularized osseous mass which forms the principal component 
of the tumor and, from the fact that it is encompassed by den- 
tine, must have originated from the pulp of the root. Heider,* 
who previously described this malformation, was inclined to 
regard it as an instance of the fusion of a normally formed 
wisdom tooth with a malformed supernumerary dental germ. In 
my opinion, the supposition of a supernumerary dental germ 

* Mittheilungen des Centralv. deutscli. Zahnarzte, 1860. 



170 PATHOLOGY. 

cannot be entertained, from the fact of the entire absence of all 
traces of enamel in the tumor. Heider was unable to obtain 
any history of the case. 

Th. Billroth reported a case which may be classed under this 
head, from Langenbeck's Clinic in Berlin.* A girl, sixteen 
years of age, complained for several months of a swollen and 
painful cheek on the right side. During the same period, the 
second right (large ?) molar of the upper jaw acquired an ob- 
lique position and a slight displacement inwards, and at the 
same time, a hard mass made its appearance upon the outside, 
which the patient supposed to be another tooth. She was 
utterly ignorant as to the length of time during which the latter 
irregularity had existed. On examination, the external wall of 
the antrum was found to be distended, where an indistinctly 
defined, hard tumor, the size of a walnut, could be felt. Neither 
the tooth nor tumor were movable. With a stout English for- 
ceps, both were seized and extracted together. The mass was 
of a bony hardness, the size of a walnut ; its upper surface was 
very uneven, warty, and entirely destitute of soft parte, the 
whole tumor presenting an appearance as if it had been wedged 
into a sort of large alveolus. The tooth was firmly attached to 
the tumor, its roots apparently being entirely imbedded in the 
new formation. No second crown could be discovered any- 
where. The surface of a section resembled very much the pol- 
ished surface of an agate. Microscopical examination showed 
it to be made up principally of dentine, with cavities and canals, 
and bone-corpuscles, which were of extremely irregular forms. 
No enamel was to be found. 

7. Double or Twin-formations.— The essential characteristic 
of these is, that instead of a single, there is formed a double 
dental germ, which remains inclosed in a single dental sac, and 
as a result of this, a partial or complete fusion of the twin- 
formations ensues. There are, consequently, two crowns and 
two radical portions belonging to the same kind of tooth. 
Herein lies the distinction between twin-formation and the 
fusion of two teeth. Sometimes the development of one of the 



;: Virchow's Archiv., Bd. viii. 



IRREGULARITIES OF STRUCTURE. 171 

pair is considerably retarded, and, ultimately, it may present 
such a deformity, that the form of the crown, or root, which should 
denote the kind of teeth to which it belongs, is unrecognizable, 
and, therefore, the basis is lost for determining whether or not 
the case is one of twin-formation. 

The only cases of twin-formation in man, as far as I know, 
which have been observed up to the present time, are those of 
wisdom teeth, and such a one is described in the Atlas, Fig. 
20. Whether they occur with other kinds of teeth is a question 
to be decided by more extended investigations. Animals, also, 
occasionally present deformities of this kind, and A. Friedlow- 
sky reported* an instance of twin-formation of the left tusk of 
an elephant, the one on the right side being stunted in its 
growth ; the former is composed of two of unequal size, the 
larger of which is wound around the smaller in the form of a 
long spiral ; the anterior segments of both roots and the greater 
portion of the bodies are fused together, but the apices of the 
tusks are separate. 

8. The parenchyma of the embryonic dental pulp degene- 
rates in various ways which are imperfectly understood. The 
unique case observed by Robinf may, as VirchowJ states, be 
regarded as one of fibrous degeneration ; in this case, there 
was found upon the lower jaw of a child, two and a half years 
of age, apparently a fibrous tumor, in which papillge with quite 
distinct dentine and enamel could be recognized. 

Virchow designates Leisering's case, observed upon the 
lower jaw of a calf, as a myxomatous proliferation of the dental 
germ. This was developed in the vicinity of the sixth molar, 
forced the dental wall asunder, and made its appearance as a 
free polypoid tumor, three inches in length and seven and a 
half inches in breadth. It presented upon its surface papillae, 
which here and there were covered with quite firm enamel and 
dentine and, besides, was composed of connective tissue, blood- 
vessels, dentinal cells, &c. 

9. A very remarkable series of phenomena is presented by 

* Sitsungsber. der Wien. Akad. d. Wiss., 1869. 
f Mem. de la Soc. de Biologie, 1863. 
| Krankhafte Geschwiilste, Bd. ii, p. 57. 



172 



PATHOLOGY. 



dentigerous cysts, where several germs, belonging to the same 
kind of teeth, (?) are contained within a capsule of connective 
tissue. Nekton found eight bodies in a dental cyst, and pro- 
nounced the case one of multiple dental formations within a 
single alveolus. Broca modified the latter view, and asserted 
that the eight bodies were not dental follicles, but dental germs 
which arose from an eight-fold division of the original dental 
germ. 

Imperfectly Developed Teeth in a Multilocular Ovarian I 
— In concluding the subject of anomalies of formation, I will 
add some observations with reference to teeth, which, though 
they do not come within the province of the dentist, still deserve 
an interest on his part ; but I must express my regret that I 
have been unable to obtain more than the following single 
of teeth in ovarian cysts. Dr. Weinlechner extirpated, with a 
successful result, a multilocular ovarian cyst, about the size of 
the fist. The largest cyst, oval in shape, measured 7.5 cen- 
timetres, in its long diameter, and 
inclosed a disk of bone twenty- 
seven millimetres in diamet 
attached to a cushion of dermal 
tissue which was the seat of a 
growth of hair. Into this disk 
are inserted three teeth which are 
surrounded by a fold of mac 
membrane. The contiguous ex- 
ternal skin may be divided into 
two portions, one covered with 
woolly hair and flattened, conical. 



Fig. 71.* 




* Fig. 71 shows three upper teeth implanted in a slightly convex disk of 
bone and, behind these, a pad of skin with long hairs. Taken from a multi- 
locular ovarian cyst. The middle tooth is the largest : its crown corresponds 
with that of a permanent molar; its roots, resembling those of wisdom 
are bent in the shape of a bow. The long diameter of the oblong , 
measures eleven, and the short diameter eight millimetres. The adjacent 
milk molar to the left has an inclined position ; that to the right ah 
responds with a milk molar. The three teeth are surrounded bv a amooth 
mucous membrane, which extends to the pad of dermal tissue and becomes 
continuous with the external skin which is furnished with hair. Natural 




IRREGULARITIES OF STRUCTURE. 173 

comparatively large papillae, and the other furnished with tufts 
of glossy, dark pigmented hair. This dermal tissue presents a 
thickness of four millimetres in its thickest portion, and is con- 
tinued in the form of a thin layer over the cyst-wall, the latter 
being about one millimetre or less thick. Numberless hairs also 
are implanted everywhere in the thin layer of skin. 

By the removal of the periosteal layer of the bone together 
with the hairy cushion of skin, a very singularly-formed osseous 
framework was brought into view beneath, forming a continua- 
tion of the osseous plate into which the 
three upper teeth are inserted (Fig. 72). 
This plate, which is to be considered as 
the rudimentary upper jaw, presents an 
outer, i. e., turned towards the cyst-wall, 
convex and smooth, and an inner, con- 
cave, uneven surface. Upon the latter ' ' 
project the roots of the teeth. Upon the 

continuation of the osseous framework behind the rudimentary 
upper jaw rise two perpendicular, tolerably thick, compact, 
slightly curved, osseous laminae, which terminate in blunt- 
pointed processes that incline towards each other. The basal 
portions of the laminae are united in the direction of the dental 
plate and partially, also, upon the opposite side ; and hence an 
incomplete excavation is formed, which is filled with an unctuous, 
fatty mass (cerebral ?), and lined with a separable fibrous mem- 
brane ; adherent to the anterior portion of the excavation are 
two black pigmental masses of lax connective tissue, the size of 
millet-seeds, containing several groups of epithelium cells with 
black pigment together with cords containing pigment (belonging 
to the choroidea ?). Several apertures also found here probably 
serve for the passage of bloodvessels and nerves. 

In two other cysts rudimentary fragments of the jaw were 
found in the form of osseous plates in which teeth were implanted. 



* Fig. 72 shows an osseous framework presented by the previous specimen. 
Posterior view, a, a, blunted, convergent, terminal extremities of the two 
elevated osseous lamina?. At the bottom of the cavity are three apertures 
for the transmission of bloodvessels and nerves. Natural size. 




174 PATHOLOGY. 

The larger plate has a discoid form, a diameter of nearly two 
centimetres, and is from 0.5 to 4 millimetres thick. The ex- 
terior surface, i. e., the surface turned towards the cyst- wall, is 
smooth and slightly convex, while the interior is occupied by 
several irregular osseous protuberances. From one sharp edge 

of the plate projects the crown of a 
milk molar (Fig. 73), which, on close 
inspection, presents a defect in the 
enamel ; the outer segment of the 
crown and roots, also, is wantii. 2 
'■ gives to it, when viewed from the ex- 
ternal wall of the plate, the appear- 
ance as if it had been split longitudi- 
nally. Upon the other side of the 
plate rises a perpendicular process of bone which has a cylindri- 
form shape, is excavated at the upper part and, upon on< 
of its base, presents a shallow cavity which is traversed by 
several osseous trabecule. Upon either side of the pi 
minute foramen and a groove for the afferent bloodw 
nerves. The greater portion of the osseous plate, in thifl 
as in the one previously described, was covered with a cushion 
of skin and a growth of hair. 

Again, in a third cyst, with a small, flattened fragment of the 
upper jaw, two teeth, in this case still concealed within the gum. 
were found, next to a tegumentary cushion, having conical 
papilla flattened upon two sides and covered with hair. The 
membrane stretching over the crown presents an appearance 
exactly like that which is found at the time of the eruption of a 
normal tooth, that is to say, clouded interlacing bund; 
fibrous tissue, without perceptible vessels, and nuclei, form the 
principal portion. One of the teeth, a bicuspid (Fig. 74 . 
presents a hook-like bend at the extremity of the root, and a 
notable peculiarity. If, namely, the general course of the thin 



* Fig. 73 shows an osseous plate taken from a second cyst of the same 
ovary. View of the internal surface directed towards the cvst-oavi: 
(a) is inserted an imperfectly-developed lower milk mol i radicular 

process of bone (rudimentary ascending ramus of the lower jaw). Natural 



IRREGULARITIES OF STRUCTURE. 



175 



Fig. 74.* 




cement be traced, it will be seen, that it invaginates the dentine 
near the extremity of the root, where it is continued as a sharply- 
defined luminous zone (globular masses 
with interglobular spaces) between the 
outer and inner dentinal segments. The 
dentinal canals, commencing at the pulp- 
cavity, terminate at the luminous zone in 
anastomotic loops, or in its interglobular 
spaces. The pulp-cavity and canal are 
of nearly equal breadth, and inclose a 
pulp, presenting the condition of net-like 
atrophy. The enamel is well developed. 
In my opinion, the condition presented by 
the dentine, in this case, is an indication 
of the occurrence of an interruption to the dentinal develop- 
ment ; in the interval, the process terminated with the forma- 
tion of globular masses, and subsequently the growth of den- 
tine ensued in a regular manner. The second milk molar of 
the same cyst presents upon its neck a distinct defect, with 
sharp edges, in appearance as if a file had been used upon the 
crown. A sclerosed, clouded mass of connective tissue was ad- 
herent at this point. Without doubt, more extended investiga- 
tions, with reference to the teeth contained in ovarian cysts, 
will prove a fertile field for the study of anomalies of teeth. 
The imperfectly-developed bicuspid mentioned by Richard Owenf 
also presents an anomalous formation similar to that of the upper 
bicuspid in the figure. 



* Fig. 74 shows a section of an upper bicuspid from a third cyst of the 
same ovary. The crown, neck, and commencing portion of the root are 
well developed. The apex of the root presents a strong fiexion. In general 
the tooth has an appearance as if a fresh cylindrical piece of dentine had 
been inserted into the tooth prior to the closure of its root. Magnified 4 
diameters. 

f Odontography, Plate 124. 



176 INFLAMMATIONS. 



II. INFLAMMATIONS. 



Dental Pulp. — When we consider the great amount of ill 
usage to which the teeth are subjected, we may well wonder that 
primary or idiopathic inflammations of the pulp are not of more 
frequent occurrence. J. Tomes goes so far even as to say that, 
in ninety-nine out of a hundred cases, the diseased action is con- 
sequent upon perforation of the pulp-cavity by caries. H eider,* 
also, expresses a similar opinion. 

The difficulties attending the recognition of an idiopathic in- 
flammation are rendered still greater from the fact that, in 
making the diagnosis, caries is to be excluded, and thia 
difficult matter to determine in not a few cases. Again, an in- 
flammation of the periosteum of the root may be misinterpreted 
as one of the pulp. A third element of difficulty lies in dis- 
tinguishing between a commencing inflammation and the hyper- 
esthesia of the pulp which is occasioned by a congestive condi- 
tion. When the objective symptoms are wanting and it becomes 
necessary to depend upon the subjective ones exclusively, then 
the course which the disease takes can only decide the point. 
If the affection presents decided intermissions, and hyperesthesia 
of other organs, also, occurs, there will be good grounds for 
excluding inflammation. 

If we trace the history of an inflammation of the pulp, occa- 
sioned by so-called perforating caries, and, first of all, the pain, 
it will be found that the latter is localized primarily, and sub- 
sequently extends to the neighboring teeth, and even over the 
whole side of the face. The partially exposed pulp is sensitive 
to external influences ; a current of air, cold water, acid sub- 
stances, when brought into contact with it, give rise to painful 
sensations, while pressure upon the tooth is well borne, provided 
the exposed pulp is not pressed upon. The intensity of the 
pain varies according to the irritability and age of the indi- 
vidual ; frequently it is more severe during pregnancy or at the 

ubIr7 ei h SCh f ' "" ^ k ' GeSellSCh ' der Wiener Aer2te > 18 *>. Abhandl. 

uber Zahnschmerz. 



SUPPURATIVE INFLAMMATION. 177 

menstrual period. In most cases, the inflammation becomes 
suppurative, i. e. f the circumscribed portion of the surface of 
the pulp presents a purulent coating, while the latter often has 
an cedematous appearance or is covered with a limpid adhesive 
fluid. If there is no obstruction to the escape of the pus, when 
it is formed, there will be notable remissions in the piercing, 
dragging, throbbing pains ; frequently, indeed, a complete in- 
termission, and the patient is only reminded of the affected 
pulp by pain induced by special exciting causes. The acute 
form then passes into the chronic. 

In cases where the pulp-cavity is not yet exposed by the 
carious process, and the pulp is shut in by a thin layer of 
dentine merely, external influences may still produce their 
effects, even when indirectly applied. In such cases, that con- 
dition is presented, which dentists term odontalgia nervosa ex 
carie. "Inflammation," says Heider, " does not appear to be 
present, for the accessions of intense pain occur without any 
warning, and even with great intensity, but frequently, however, 
intervals occur, during which there is entire freedom from pain. 
Cold applications, which diminish the pains induced by inflam- 
mation, increase them in these cases. 

"A considerable period having elapsed," he continues, " after 
the appearance of a dark spot and the subsequent destruction 
of the crown of the tooth at the part corresponding to the dis- 
coloration, the tooth becomes sensitive to changes of tempera- 
ture ; heat and cold occasion slight and transient pains, and 
hence the patient is careful to avoid cold and hot food and 
drinks, and that side of the jaw, upon which the carious tooth 
lies, is no longer employed in mastication, because the pressure, 
even of the particles of food which are forced into the carious 
cavities in masticating, now causes quite severe pain. After 
this state of things has continued a longer or shorter period, a 
pain suddenly occurs in the pulp, usually after biting something, 
of such severity as not infrequently to bring tears into the eyes, 
and if it continues very long it becomes intolerable. In a few 
minutes, its severity diminishes to a more tolerable degree, but 
it is still quite severe and continues, perhaps, for an hour, with 
exacerbations and intermissions, and finally ceases by degrees, 

12 



178 INFLAMMATIONS. 

when an interval, usually brief, of freedom from pain ensues, 
but soon it is reproduced, for now the pulp-cavity is exposed, 
and all external agencies act directly upon the nerves. The 
patient, however, is not always free from severe pains until the 
opening of the pulp-cavity ; frequently, after the occurrence of 
transient slight pains, a mild attack is succeeded by a more 
acute and lasting toothache, with intermissions of hours, or half 
a day." 

Inflammation of pulps which have been denuded by penetra- 
ting caries, may be circumscribed or general. The former is 
found in those cases especially where the perforation of the 
hard tissues by the carious process is confined within narrow 
limits; only a portion of the body of the pulp is implicated, 
perhaps the extremity of a papilla of a bicuspid or molar. 

The most prominent indication is the redness, which is due 
either to a hypersemic condition of the bloodvessels, or to the 
imbibition, by the pulp-tissue, of the coloring matter of the 
blood, which is deposited from the red blood-corpuscles. Inter- 
mediate between the congestive and diffusive, stands the hemor- 
rhagic redness which occurs in the form of reddish points or 
spots. The borders of the extravasation generally fade away im- 
perceptibly in the parenchyma of the pulp. In cases of circum- 
scribed inflammation, the redness is limited to a portion of the 
body of the pulp, and diminishes from the periphery towards 
the centre ; it involves one or another root, or perhaps onlv the 
broader portion. The intensity of the redness varies between 
a light rose red and a deep blood red, frequently mixed with 
gray, which preponderates more or less. When* the inflamed 
pulp is accompanied by an (edematous enlargement, it acquires 
a yellowish-red appearance, and, attended by a superficial sup- 
puration, is of a pale greenish-yellow color. * 

The increase in the volume of the pulp, when swollen from 
the effects of inflammation, is restricted to certain limits by the 
resisting dentinal capsule, within which it lies, and the view has 
often been expressed, that the resistance of the capsule is the 
cause of the intense throbbing and lancinating pains. Though 
it cannot be doubted that the inflammatory toothache is modified 
by local relations, still, on the other hand, we think it should 



DENTAL PULP. 179 

"be remembered in this connection that intensive neuralgias 
occur under the most varied anatomical relations. The swelling 
of the pulp, in cases of circumscribed inflammation, is limited 
to one or another portion, but a circumscribed swelling can 
hardly be determined in many cases, and is best recognized in 
those cases where the inflammation occurs in an atrophic pulp. 

With reference to their duration, inflammations are divided 
commonly into acute and chronic, both of which present various 
degrees of intensity. The more acute the case, so much the 
more rapidly is the parenchyma destroyed, and the more chronic 
the case, the more moderate are the symptoms and the longer 
are the intervals between them. In the former case, the organ 
also undergoes a relative decrease in its consistence, and may 
even become transformed into a soft, pultaceous mass. 

The suppurative process is developed, almost always, as a se- 
quence of caries, and is limited to the superficial layer of the 
body of the pulp or of the root portion corresponding to the 
carious locality ; the suppuration manifests itself in the form of 
a greenish-gray or greenish-yellow, semi-fluid, thready covering, 
containing pus-corpuscles as its characteristic morphological 
elements. The latter, for the most part, have undergone fatty 
degeneration, so that on treating them with acetic acid, the 
numerous nuclei are obscured by the presence of the fat-gran- 
ules; indeed, it is not an uncommon occurrence for the corpus- 
cles to be so shrivelled and degenerated that they are no longer 
recognizable. The fluid basis of the purulent mass is rendered 
turbid by the fat-globules suspended in it, which latter, also, are 
presented in agglomerated granular masses. By adding acetic 
acid, the mucus is precipitated in the form of a cloudy, stringy 
mass. 

Cases are met with frequently, where not a single pus-cor- 
puscle, but mere agglomerations of shrivelled, turbid nuclei im- 
bedded in a mass resembling coagulated albumen, are to be 
found, in the superficial, apparently purulent, substance. 

If the examination is extended from the purulent, infiltrated 
portion of the pulp to the deeper layers, it will readily be seen, 
in acute cases, that a proliferation of the cells of the paren- 
chyma has taken place and may be traced into the internal por- 



180 INFLAMMATIONS. 

tions even far clown into the root-pulp. In order to show this, 
it is well to place sections of such pulps in paraffine, glue, or 
some other suitable substance. The connective-tissue cells of 
the pulp, especially in young individuals, sometimes present a 
marked proliferation. For instance, binucleated, roundish, and 
spindle-shaped cells, are frequently observed, as the principal 
forms, and these, together with many others derived from them 
and variously shaped, occur in such large numbers that they are 
closely compacted, especially in the vicinity of the focus of in- 
flammation. Finally, still more closely packed, agglutinated, 
elementary organs are found, consisting, usually, of a round 
nucleiform body surrounded by a layer of protoplasm which be- 
comes exceedingly small. 

If we examine the bloodvessels, structural changes may be 
discovered at the points where they pass into the focus of in- 
flammation, as follows: A swollen and lax condition of the 
fibrous sheaths of the small arteries and veins; a cloudim 
the sheaths, occasioned by scattered or aggregated fat-granules, 
or by larger or smaller nuclei, often in clusters, which not infre- 
quently surround the entire vessel, whereby the eharact* 
elements of the bloodvessel are lost, and it can onlv be recog- 
nized by its continuity. Albrecht* called attention to the no- 
table increase in the volume of the vessels and to their direc- 
tions, which, instead of being in straight lines, are exceedingly 
tortuous. t 



* Krankheiten der Zahnpulpe, 1858. 

f This condition is observed especially in connection with chronic inflam- 
mation. The prolonged and frequently repeated, augmented pressure of the 
blood occasions a diminution of the elasticity and contractility of the vas- 
cular walls; coincident with the proliferation of the connective-tissue ele- 
mentary organs, the vessel loses a certain amount of its basis-tissue which 
has become succulent; after expansion, it cannot recover its former length 
or transverse diameter, but becomes longer and wider, acquires lateral 
flexions, and frequently varicose expansions which, when they lie superfi- 
cially, easily rupture and give rise to the above-mentioned extravasations of 
blood ; the latter subsequently occasion pigmental degeneration and cloudi- 
ness. 

When the vessels are permanently expanded, disturbances of the circula- 
tion are more liable to occur. The interchange of materials in proper 



DENTAL PULP. 181 

The bundles of nerve-tubes in the vicinity of the focus of in- 
flammation, also, present evidences of structural changes. The 
most notable indication is afforded by the cloudiness produced 
by deposits of fat-granules which, partly disseminated and 
partly aggregated, are deposited between the nerve-tubes and 
also in their interior (neuritis). The fat-granular metamorpho- 
sis does not uniformly involve the medullary matter even of one 
bundle of nerves, that is to say, the nerve-medulla of indi- 
vidual nerve-tubes is unaffected by fatty degeneration. Some- 
times, groups of oval or round nuclei, analogous to those in the 
bloodvessels, are met with in the fibrous sheaths of the nerves, 
and indicate a proliferation of the connective-tissue elementary 
organs (Atlas, Fig. 80). 

Hence it may be concluded that the occurrence of inflamma- 
tion in the nerve-bundles of the pulp, whether it results in a 
fatty degeneration of the nerve-medulla or in a cell prolifera- 
tion of the interstitial connective tissue of the bundles, necessi- 
tates a disturbance of the conductibility of the axis-cylinder, 
which is manifested by a sensation of pain. 

The protoplasm of the dentinal cells, in the vicinity of the 
focus of inflammation, is rendered cloudy by fat-granules ; their 
cohesion becomes lax, and gradually they undergo complete dis- 
integration. 

In cases which run an acute course, the fatty metamorphosis 
is more intensive and extensive than in chronic cases, and, co- 
incident with this, occurs the production of a lax condition of 
the pulp-tissue, and subsequently dissolution ensues, so that, 
finally, there remains merely a discolored membrane adherent to 
the still intact wall of the pulp-cavity and prolonged into the 
root-pulps and containing the shrivelled remains of the pulp. 

From a general view of the phenomena attending an inflam- 
mation of the pulp, it appears that the anomaly in the inter- 



amounts, can no longer continue, so that excretory elements are retained, 
which in turn occasion still further impairment of function. 

In consequence of the stagnation of the blood, both the red and white 
corpuscles become necrotic; the former yield their coloring matter to the 
fluid in which they are immersed, and the pulp becomes impregnated with 
the coloring matter of the blood. 



1S2 INFLAMMATIONS. 

chapge of material is manifested by an augmented supply and 
diminished withdrawal of the blood, an increased transudation, 
and an accumulation of excretory materials : further, by a pro- 
liferation of cells which form the stroma of the pulp and the 
connective-tissue investments of the bloodvessels and nerves, 
and by an abundant development of pus-corpuscles or unusually 
large, rapidly shrivelling nuclei, which prolifications, together, 
induce a partial or complete disorganization of the parenchyma 
of the pulp. 

Acute inflammation of the pulp frequently results in a 
grenous destruction ; usually this is a sequence of caries of the 
milk and permanent teeth, but it also occurs after inflammation 
of the root-periosteum and, more rarely, is developed indej 
ently. As is the case with other organs, two principal foi 
gangrene of the pulp are distinguished, the so-called moist and 
dry. The former is characterized by a dirty deep red. b 
ish-red, reddish-gray or greenish-gray discoloration ; a diminu- 
tion of the consistence to that of a thick, pultae< 
which has a decided penetrating, fetid, characteristic 
ous odor. Sometimes, also, the pulp becomes transformed into 
a pulpy, unctuous, caseous, disintegrated mass, with a nauseating 
odor. 

The inflammatory character of the changes in the tissues may 
be recognized, unless the gangrene has made too great 
and, for this purpose, it is well to commence the in* 
in the root proper and to continue it in the direction of the 
coronal pulp. The sheaths of both the nerves and hi 
exhibit the above-mentioned prolifications, which increase pro- 
portionately as the gangrenous focus is approached, and finally 
cover the whole field of view. The evidences of far 
ration, also, are apparent in rapidly increasing prog 
Here and there, the contents of the nerve-tubes are die 
grated. The walls of the bloodvessels have a fat-granular ap- 
pearance and disintegrate as if they had been macerated ; the 
oblong nuclei of their organic muscular fibre layers art 
tered in confusion. Where the gangrenous destrueti - 
plete, a dirty yellow, brownish-yellow molecular detri: 
found, containing, generally, numerous interposed. 1 



DENTAL PULP. 183 

shaped, fatty acid crystals, similar to those found in the sputa 
in gangrene of the lungs. 

In the so-called dry gangrene, nothing is left of the pulp but 
a blackish-brown, brownish-red, tinder-like, shreddy or mem- 
branous, slightly moist mass, which only partially fills the pulp- 
cavity, the remaining space being occupied by a gaseous fluid. 
The principal histological elements comprise red or dark-brown, 
cylindrical masses (necrotic blood) inclosed within still recog- 
nizable sheaths (bloodvessels), dirty yellowish or brownish ag- 
glomerations of nuclei, diminutive pigment grains, crystals of 
haematoidin. 

In most cases there is no perforation of the pulp-cavity, though 
caries has preceded the gangrenous condition of the pulp. In 
certain cases filling the tooth may be the predisposing cause. 
The primary gangrene appears to occur particularly in teeth 
which have been worn away by attrition. Besides these causes 
there are general, obscure, injurious external agencies which 
also promote the occurrence of gangrene in the inflamed pulp. 

When the red coloring matter of the blood-corpuscles transudes 
through the intact vascular walls, or escapes from the corpuscles 
after the rupture of the latter, it penetrates the dentine and im- 
parts a reddish color to the teeth,* which generally is first 
noticed upon the neck of the tooth, where the enamel about the 
dentine terminates. In many cases the redness, which is a pale 
rose color, is limited to a short streak upon the neck in the 
vicinity of the root, and fades away towards the latter. In 
other cases the redness is more intense, and spreads towards 
the extremities of the roots, being more marked, generally, 
upon one side than upon the others. The coloring may, how- 
ever, be most decided even upon a portion of the root. 

If sections are made to show the amount of the redness pre- 
sented by the different dentinal layers, now and then instances 
are met with where the inner dentinal zones, towards the pulp- 
cavity or canal, exhibit very slight or no redness ; next to this 
is a broader or narrower middle zone of a brighter tinge, which 



* M. Heider und C. Wedl iiber gerothete Zahne : Deutsche Viertelj. f. 
Zahnheilk. 18G3. 



18-i INFLAMMATIONS. 

passes into the weaker color of the outer zone. Sometimes the 
inner dentinal zone is the most highly colored. 

Thin sections furnish a clear idea of the relative amounts of 
the coloring substance in the different dentinal zones. The 
dentinal canals are filled with the red coloring matter, from 
their origins even to their most delicate ramifications, while the 
basis-substance, apparently, is not colored in the least. The 
coloring matter presents the red hue of the blood and has the 
appearance of a homogeneous, not granular, substance filling 
the canals. It is evident that these appearances are not due to 
the phenomena of interference, from the fact that Bectioi 
normal teeth do not present such discoloration-, 
known, similar colorings may be produced artificially, i . </.. by 
means of carmine, madder, Prussian blue, blood-red. »\c. It 
may quite readily be shown by experiment, that the cement 
takes up none of the coloring matter. If the latter is allowed 
to act from the pulp-cavity, the dentine becomes colored, while 
this does not ensue if the root of the tooth is surrounded by the 
coloring matter, a fact which is self-evident if tin nal is 

closed.* 

The varying degrees of redness presented by the different 
dentinal layers may be referred to various causative condil 



* We immersed dried human teeth, the crowns of which were brok 
in the fresh blood of a rabbit dilated with about one-fourth the amount of 
water, upon which a layer of oil was poured in order to prevent v 

About forty-eight hours afterwards, the dentinal surfa- - 
found to be colored more or less, in some places a deep red. in other.- . 
rose-red. Sections were made, which showed the red coloring matter de- 
posited within the dentinal canals. 

In order to solve the question, whether the red color is imparted to the 
dentine in a direction from the root-canal or from the cement layer, i. <•., 
from the inside or from the outside, the following experiment was 
glass tube, sis inches in length and of a suitable diameter, was Btted 
opening into the pulp-cavity of a lower molar. Babbit's bl ben in- 

troduced into the tube until a column stood above the pulp-cavity. Further, 
some teeth, which were quite intact, were placed in fresh rabbit's blood, the 
openings of the canals at the extremities of the roots having previous] . 
closed with sealing-wax. The result of the two experiment- - 
In the first case the dentine acquired a very deep red color, while in the 
latter not even a trace of discoloration was perceptible in ^ . - ions off 

the teeth. 



DENTAL PULP. 185 

It is to be remembered that the middle dentinal zone is traversed 
by more numerous ramifications of canals than the inner one. 
Our perception of the red color of the dentine must be the effect 
of the totality of the reddened canals which are visible to a 
certain depth through the basis-substance. If the latter presents 
various degrees of transparency, then the red coloring will also 
exhibit corresponding modifications. The reddish-yellow, rose- 
red or gray-red, or reddish-gray color of the different teeth, 
and the various shades in the several dentinal zones, are not 
due to casual variations in the coloring matter of the blood, nor 
to the diminished imbibition of the latter (one can satisfy him- 
self, even by inspection, of the uniform coloring of the tubules), 
but within certain limits are dependent upon the degree of trans- 
parency of the dentinal basis-tissue. With caries of the teeth, 
with atrophy of the dental pulp, the dentine, as is well known, 
presents a dirty white, sometimes yellowish-gray color, particu- 
larly towards the pulp-cavity and dental canal, in localities, in 
fact, which the caries has not attacked. Accompanying this 
condition there is diminished transparency of the basis-sub- 
stance in the inner dentinal zone, which obstructs the perception 
of the coloring matter within the canals. The degree of redness 
depends, also, upon the disposition of the reddened canals. If 
the dentine is arranged in such a manner that only small por- 
tions of the canals are presented to view, as it were in cross- 
section, then the sensation of redness produced will be less 
marked than if they are arranged with their long dimensions 
exposed to view, so that a larger quantity of the coloring matter 
is presented to the retina. 

Since the dentinal canals inclose the ramifications of the pro- 
cesses of the dentinal cells, it appears much more reasonable to 
assume a process of imbibition by the latter, rather than capil- 
lary attraction. 

The occurrence of reddened teeth is confined principally to 
such as are carious, whose pulps present a deep-red color or ex- 
travasations of blood, which latter correspond in location to the 
reddened portions of the dentine. It is, also, a well-known fact, 
that when incisors are treated with arsenic or caustic paste pre- 
vious to the operation of filling, their crowns acquire a rose-red 



186 INFLAMMATIONS. 

color in the course of a few weeks or a month after the operation 
of filling. This discoloration often occurs without any symptoms: 
frequently, however, it is attended by symptoms of a congestion, 
and this is the case always with teeth whose pulps were not re- 
moved after the application of caustic paste.* Moreover, red- 
colored teeth are observed also as a post-mortem appearance, 
after cholera, typhus, and death by suffocation. Rose-red teeth, 
with a variation in the shading upon the different sides, occur 
also as a variety of formation. f 

Chronic Inflammation of the Pulp. — The anatomical appear- 
ances which characterize this affection comprise a more limited 
extension of the usually pale redness; diminished succulence 
and greater consistence of the tissues; limited, usually not very 
pronounced, proliferation of the connective-tissue elementary 
organs in the portions denuded by the carious process ; some- 
times superficial suppuration; in many coses, an atrophic condi- 
tion of the pulp, particularly net-like atrophy in which extrava- 
sations of blood are commonly found ; a secretion of a serous 
fluid' with an offensive odor like that of macerating bone, which 
however does not properly belong to the fluid, but is generated 
by the putrefaction of the organic constituents of the dentine. 
The paroxysms of pain are less severe and less prolonged as a 
rule. Indeed there may be no pain, if there is no obstruction 
to the escape of the usually thin serous or purulent fluid upon 
the surface of the exposed portion of the pulp. Hear. cold, 
chemical or mechanical injuries of the exposed portion, always 
produce an uneasy sensation which may be increased ro severe 
pain. 

Chronic Abscesses in the Pulp, independent of Curie*, are 
very rare. The case illustrated in the Atlas, Fi^r. 51. of calci- 



[The pulp often dies as the result of the use of arsenic to obtrude sensitive 
dentine, even when it is left in the cavity of decay hut a short time. In 
these cases the tooth almost always becomes reddened. For this reason, in 
this country, the use of arsenic, except to devitalize the pulp, has been almost 



if nnt onHr.^1 • \n — ' "**■"*"■ lu ueN "*«wj me puip, nas been almost 

L!t W * g,Ve " UP ' EVe " Whe " U 1S HSed fOT d «*"^S «" P»1P. «n- 
Zal 77"? '• ' Mde thr ° Ugh the ™»* at »• Pulr-oavitv \h . .he 

tads n,ay find ex.t, nitration of the dentine and diLCion foU.w.- 

t Heider aus der Praxis : Deutsche Tiertelj. f. Z., 1862. 



ABSCESSES IN THE DENTINE. 187 

fication of the root-pulps of a grooved molar of the upper jaw 
may, perhaps, be regarded as a case in point, where the coronal 
pulp contains, besides calcareous deposits, a cyst-like, spherical, 
quite large cavity, with smooth walls, which is separated by a 
transverse membranous expansion from an analogous cleft-like 
cavity extending to the bottom of the pulp- cavity. There is, to 
be sure, no actual proof that the cavity in question is that of an 
abscess ; but the only other probability is that it is the cavity 
of a serous cyst. Still more rare is the occurrence, in man, of 
an excavation of the coronal portion, extending into the dentine, 
as the result of an abscess. Th. Bell * reported a single case 
which came under his observation. A physician suffered, for a 
long time, from severe pain in the right side of the upper jaw, 
apparently referable to the second molar tooth which, however, 
presented no external evidences of disease. After some time 
had elapsed, an inflammation of the root-membrane ensued, and 
the tooth became loosened a little. It now was obvious that 
this tooth was the source of the pain, which finally became in- 
tense, and so it was extracted ; as its exterior presented no in- 
dications of disease, Bell divided it with a saw, at the upper 
part of the crown, and found a completely circumscribed cavity 
in the dentine; the surface was white and apparently sound 
and unbroken. The rest of the tooth did not present the least 
evidence of disease, excepting that the root-membrane, which 
had been inflamed for a long time, had also begun to suppurate. 
It seems, remarks Bell, that the inflammation arose primarily 
in the dentine, from some local cause ; that the bloodvessels of 
the dentine (of the pulp, rather) developed suppuration, and ab- 
sorption ensued in consequence of pressure, and, in this way, a 
cavity was produced for the reception of the pus. We shall 
frequently have occasion to refer, in the following pages, to the 
fact, that pus produces a " usure," a wearing away (usurire) of 
the dentine. 

In the teeth of large mammals, abscess cavities will be found 
quite frequently in the dentine, if one only takes pains to search 
for them. 

* Op. cit., p. 173. 



188 INFLAMMATIONS. 

. The tusks of elephants, on account of their large size and 
great projection, are exposed to manifold mechanical injuries, 
and it is, also, a well-known fact, that it is not an uncommon 
occurrence, in working ivory, to find bullets imbedded in the 
tooth, which then presents pathological changes, that render it 
unsuitable for the purposes of the ivory turner. The attention 
of Goethe* was attracted long since to the changes in ivory 
which are produced by bullets imbedded within it ; he speaks of 
cavities in the diseased limits, which are partially lined by a 
delicate membrane. 

We are indebted to J. Tomesf for the very thorough descrip- 
tion of cavities of this nature in two tusks. The dentinal sub- 
stance in each of the two tusks presented a newly-formed cavity, 
having no connection with the pulp-cavity, nor indeed any out- 
let. One of them was quite empty, dry, and contained a 
quantity of a desiccated membranous mass, or a fluid, which 
was apparent in the most dependent portion of the cavity, where 
it had become inspissated. In the other case, the cavity was 
broader, also without any outlet, encompassed by dentinal sub- 
stance and lined with a dried membrane ; here and there, small 
spinous processes of dentinal substance projected from the walls 
of the cavity. The dentine encompassing the cavity had a 
veined appearance like marble, occasioned by the different di- 
rections assumed by the dentinal tubules, ami also was tra\ 
by numerous canals of the character of bloodvessels and visible 
to the naked eye. The lining membrane of the cavity was 
taehed and macerated in water, and proved to be a fibro-cellular 
tissue. According to these statements. Tomes appears to have 
taken no notice of the new formation of osseous substance 
around the abscess-cavity.J 

Albrecht holds the view, for which there are grounds, that 
the vessels in the dentine of the second case can have been 
formed only by the prolongation of the vessels of the pulp. He 
assumes, then, that vaso-dentine does not occur in the tusk of 
the elephant. According to E. Owen,§ small bloodvessel* 



* Osteologische Mittheilungen, 1798. 
f Albrecht, Krankh. d. Zahnpulpe, p. 23. 
X Compare New-formations. 
\ Odontography. 



ABSCESSES IN THE DENTINE. 



189 



tend forward in the axis of the tusk as far as its apex, and the 
bloodvessels may, also, penetrate, even to the dentine, from those 
of the root-membrane, if the abscess-cavity be located near the 
outer surface. 

By the kindness of Prof, von Schroff, I had the opportunity 
of examining segments of elephants' tusks which were labelled 
ulcers. They contain extensive abscess-cavities in the dentine, 
apparently entirely shut in, of the size of a pigeon's, a hen's, 
even of a goose's egg and, here and there, present irregular 
parietal sinuations. The cavities are lined by a desiccated, 
dirty-yellow, brownish-yellow, dark-brown and black mass. The 
portions adjacent to the cavities have a mottled look, and con- 
sist, principally, of vascularized osseous tissue, which forms a 
layer of varying thickness encompassing the abscess-cavities, 
dips more or less deeply into the dentine, and presents in sec- 
tions various sinuations and islands (Fig. 75). If we trace the 



Fir;. 75.* 




process of resorption of the ivory from the side of the en- 
croaching osseous tissue, it will be observed that both the main 

* Fig. 75 shows a section from the tusk of an elephant, containing a large 
abscess-cavity which upon one side approaches to within six millimetres of 
the periphery. It presents various cup-like excavations and is lined with 
an adherent, dried, dirty brownish-yellow mass. That portion of the wall 
which incloses the inferior segment of the cavity, is transformed into an 
ununiform tissue (a) (osseous tissue) to a depth of five to ten millimetres, 
the line of demarcation between it and the normal dentine being sharply 
defined. This tissue has a wavy outline, a spotted and striped appearance, 
and its consistence is less than that of normal dentine. Two-thirds natural 
size. 



190 INFLAMMATIONS. 

trunks and the lateral branches of the dentinal canals present 
numerous varicous expansions, while portions of them are trans- 
formed into jagged, elongated cavities, or give place to a glob- 
ular, transparent substance. In other portions, large, multi- 
radiating bone-corpuscles have encroached upon the dentine, or 
vascular canals have become surrounded by concentric lay 
osseous substance. From the wall of another a : vity, 

conical processes, one-half to one millimetre broad at th< 
and two to four millimetres in length, project into it. and 
are composed partly of a minutely lobulated (kleindr 
globular mass, together with bone-corpuscles, and partly of den- 
tinal canals, anastomosing without irregularity in various direc- 
tions and, here and there, forming tufts which extend in the 
direction of the axis of the conical proe 

A condition, also, is presented which essentially 
analogy to that observed by Tomes. The new hard formations 
upon the wall of the abscess (abscedirenden Wand) form 
parative tissue which tends to replace the Bubstanc v the 

suppurative process, and probably their development would have 
gone on still farther, so that they would have diminished the 
area of the cavity, had they been supplied with fresh formative 
material by the bloodvessels. As I had only - I my 

disposal, I was unable to make special investigations with i 
ence to the origin of the bloodvessels, which are the i 
antecedents to the production of both the new dental and 
ous tissues and, also, of the suppurative process. In all pi 
bility, the newly-formed bloodvessels were outgrowths from 
those of the pulp. The elucidation of this question remains 
for future special investigation. 

The chronic inflammation of the periphery of the a' 
(Abscesshaut), in these cases, led to the production bf 
tissues (osseous and dentinal), both of which must have 
developed from cells. But even if we are willing to admit that 
the bloodvessels of the new-formed substances are derived from 
other pre-existing ones, still the appearance of the iu 
and dentinal substance in the wall of the abscess-cavitv con- 
tinues to be an extraordinary phenomenon, and the assumption 
in relation to their appearance, that the cell-life of the' 



DENTAL PULP. 191 

nective- tissue parietes of the abscess is exalted to a differentia- 
tion, as in embryonic life, is open for discussion, since, indeed, 
we cannot by any means presuppose that the germs of the 
formative cells are transported to the part with the blood. 

As a general rule, as has been shown above at considerable 
length, inflammation of the pulp imparts a reddish color to the 
dentine. Albrecht* observed dark-colored portions of dentine 
in localities corresponding to small defects which were visible in 
the lining of the wall of the pulp-cavity and extended as far 
as the enamel layer. It was observable, however, that the dark 
color was confined principally to the dentinal canals, and was 
much less perceptible in the intervening substance. The affected 
tooth, he says, undergoes a change of color, under these cir- 
cumstances, the dentinal substance becomes gray-black and as- 
sumes the condition of a gray, pulverous, structureless mass, 
which is perceptible through the enamel layer, the latter re- 
maining intact for a much longer period. Apparently, he ob- 
served no circumscribed defect in the dentine upon the inside, 
and, indeed, this is found only very rarely in conjunction with 
a discoloration of the tooth. Dr. Steinberger informed me, 
that he could call to mind only a single instance which occurred 
in Ileider's practice, where the dentine had become softened by 
the extension of gangrene from the pulp-cavity. In this case, 
Ileider exposed and filled the cavity, and succeeded in preserv- 
ing the tooth. Cases of this kind may possibly have given rise 
to the supposition of the occurrence of caries interna (compare 
Anomalies of the Secretions). 

Chronic inflammations in the pulp lead to various forms of 
atrophy, among which, chronic fatty degenerations and calcifi- 
cations are to be mentioned especially. The new-formations, 
which are consequent upon an irritation of the elementary 
organs of the pulp, include those of dentine, osseous substance 
and connective-tissue cells (sarcomatous proliferations)^ The 
return to an entirely normal condition is very exceptional, and 
whenever there seems to be a probability of such an occurrence, 
frequent relapses will undeceive one. In fact the pathological 

* Op. cit., p. 21. f Vide New-formations. 



192 INFLAMMATIONS. 

gepms of tbe cells persist, and the latter are called into renewed 
activity under the influence of trifling causes. Chronically in- 
flamed pulps may, also, become gangrenous and transformed, 
partially or entirely, into a fetid, pultaceous mass. 

An important affection, which frequently occurs as a sequel 
of inflammation of the pulp, is that of the periosteum of the root, 
a fact easily explained, when the relations of the bloodvessels 
and nerves are taken into consideration. This membrane be- 
comes swollen, abscesses are formed, generally at the extremities 
of the roots, and the pus finds an exit into the substance of the 
gum or into other regions, to be mentioned farther on. 

Gums. — According to the locality and symptoms, there i 
tinguished a superficial inflammation of the gums, which is 
fined to the outer mucous-membrane layer, and a general paren- 
chymatous inflammation which is not limited to the ootei 
attacks, as well, the deeper layers. The character of thee 
flammations is controlled by the genetic conditions which are 
the foundation of the processes, and its determination pr 
manifold difficulties. The mere form, independent of all 
clinical evidence, affords insufficient grounds for an opinion aa 
to its character. Individual peculiarities modify th- 
effect of the disease, and the combinations of different 
produce a variability in the phenomena. In many cases it is 
possible merely to make distinctions with reference to the C 
of the disease, that it is acute or chronic. Every inflamm 
of the gums may give rise to a superficial or deep destracti 
the substance of the gum and, likewise, may cause a destruction 
of neighboring tissues. 

In catarrhal inflammation of the -urn, the latter assumes a 
rose-red color which is most apparent upon the fr< 3 ; sub- 

sequently, white spots appear and disappear, which are produced 
by the exfoliation of the epithelium. The gnm feel, uniformly, 
though not notably, swollen, smooth, and hot. The patient 
complains of annoying sensations of itching, tickling, and burn- 
ing which are diminished temporarily by grinding the teeth. 
A livid gray, mucilaginous, frequently puriform secretion col- 
ects in the pockets formed by the gum, and oozes out. when 
the finger is pressed along its border. 



GUMS. 193 

This inflammation occurs most frequently upon the labial 
surface of the incisors and canines of the lower jaw, and more 
rarely upon the same surface of the corresponding upper teeth. 
In the latter case, the covering of the hard palate of the affected 
side becomes involved. Still more rarely are the gums of the 
bicuspids, and almost never are those of the molars attacked. 
The affection either is limited to the gums of a few teeth merely, 
or invades those of all the incisors and canines of one jaw, less 
frequently of both jaws, and never those of all the teeth of 
either jaw. 

The inflammation *may continue months and even years, par- 
ticularly upon the lower jaw where the secreted fluid accumulates 
within the pockets formed by the gums. In cases of unusually 
long duration, it spreads to the periosteum of the root, gives 
rise to resorption of the margin of the alveolus and loosening of 
the tooth in its socket. 

The more acute forms, in most cases, are due apparently to 
the same causes which generally give rise to catarrhal conditions, 
to excessive variations in temperature, damp and cold weather, 
&C. Another very frequent cause, particularly of inflammation 
of the gums of the incisors and canines, is the prolonged, con- 
tinually-repeated mechanical injury, to which these teeth are 
subjected in closing the jaws, when several molars and bicuspids 
are wanting. With the latter condition the incisors and canines 
are pressed together more firmly in chewing and experience 
slight movements in their sockets, whereby the gums and root- 
membrane become irritated and swollen. As the mechanical 
injury continues, a process of resorption of the margins of the 
alveoli, also, is induced, the tooth becomes loose and finally 
falls out. 

An accumulation of tartar with its rough outer surface, also, 
produces a mechanical irritation of the margins of the gums 
and gives rise to a chronic catarrh, while the secretion of the 
latter, on the other hand, occasions an increased formation of 
tartar. Each process, consequently, promotes the development 
of the other. 

In cases where caries has destroyed the greater part or the 
whole of the coronal portion of the tooth, the sharp edges of the 

13 



I 

194: INFLAMMATIONS. 

cup- shaped carious cavity become a source of irritation of the 
margins of the gums ; the putrid products of decomposition, 
which result from the carious process, also have a similar effect. 
If the neck of the tooth, also, or a portion of the root is destroyed 
by caries, the gum loses its support, becomes detached, inverted, 
and acts as an additional constant source of irritation. 

With tobacco chewers and those who smoke filthy pipes and 
strong cigars, especially if they do not pay proper regard to 
cleanliness, the tobacco juice becomes an important source of 
irritation. 

Catarrhal inflammation is observed, also, as an accompaniment 
of catarrh of the intestinal tract. 

The character of the catarrhal secretion is essentially modified 
by the constitutional peculiarity of the individual. In tubercu- 
lous people, generally a very abundant, frequently puriform, 
secretion is observed, and the affection is usually very obstinate, 
while with individuals who are healthy in other r 
appears directly on the removal of the irritating c a . Super- 
ficial ulceration of the gums is a not uncommon sequel of a 
neglected or obstinate catarrhal inflammation ; such ulcei 
flattened and covered, at the base, with a firmly-adherent 
mass; they heal finally without leaving a perceptible breach of 
substance. 

If the old epithelium, even in the minor catarrhal affecti 
is not removed, but, remaining adherent, becomes mixed with 
the debris of food, and if, in addition, there is also a gastric 
catarrh, the cells become disintegrated, their contents thickened, 
and between the layers are found the familiar ferment 
fungi (mucor), which are very abundant in mucus, under the 
favorable conditions afforded especially by individuals pn - 
ing evidences of impaired nutrition, e. </.', in the ma: 
infants or the emaciating diseases engendered bv unhealthy 
surroundings (thrush). The mucous membrane which has now 
acquired a deep red color is beset with soft, white nodules, or is 
covered with membraniform layers which may be stripped off; 
the latter spread to the adjacent portion of the oral m 
membrane, but rarely are attended with an ulceration. In 
of this description the catarrhal affection is not to be referred to 



GUMS. 195 

the fungi (Oidium albicans) as a cause, although, to be sure, 
there is no doubt but that the latter, in consequence of their 
enormous productivity, become a source of irritation in the in- 
flamed mucous membrane and, consequent^, tend to continue 
and add to the catarrhal process already developed. Bacteria 
are found associated with copious mucous or puriform, fetid 
secretion of the gums ; these will receive special consideration 
in connection with the subject of Anomalies of Secretion. 

In the vesicular, herpetic (?) inflammation of the gum, vesicles 
are formed which give rise to itching and burning sensations. 
The vesicles collapse or rupture and there remains a superficial 
erosion which heals without cicatrization. Usually it extends 
to regions adjacent to the gum. 

Inflammatory affections of the gum are developed in the 
course of the acute exanthemata, such as variola, scarlet fever, 
measles, and are accompanied by indications peculiar to these 
diseases. With persons affected with syphilis, who have not 
been under the influence of mercury for a long time, a very 
marked softening of the gum is said to occur, according to G. 
Delestre.* 

In mercurial salivation, according to the statements of Corfe 
which J. Tomes confirms, the action is indicated primarily by 
the gums, indeed several hours prior to the occurrence of the 
flow of saliva; according to J. Tomes the indications are as 
follows :f "The mucous membrane of the gums, where it is 
firmly adherent to the tissues beneath, assumes an opaque, white 
color, contrasting strongly with the non-adherent portion, which 
preserves its natural hue or becomes more red. The free edge 
of the gum is movable, but that portion which lies upon the 
alveolar margin is firmly attached to the periosteum, and as the 
margins of the alveoli have a festooned outline, so the whitened 
mucous membrane presents corresponding undulations. Again, 
the mucous membrane preserves its natural color, where it is 
reflected from the gum to the cheek. The diminished tenacity 
of the epithelial cells contributes to the production of the white- 
ness of the gum. When the epithelium exfoliates, the reddened 

* Du ramollisement des gencives. Paris, 1861. 
f Dental Phys. and Surg., p. 299. 



196 INFLAMMATIONS. 

papillary portion becomes exposed, and the gum acquires a 
mottled appearance." 

Lead may give rise to a partial bluish coloring of the gums. 
Dr. Brin ton* observed this condition, in a case of lead colic, 
upon the edge of the gum corresponding to the incisors of an 
entirely sound set of teeth. He regarded the blue edge as due 
to a sulphuret of lead, produced by a deoxidation of a salt of 
lead. Probably the saliva contained lead, and the deoxidation 
was occasioned by the sulphureous matter contained in the 
atmosphere. 

Croupous inflammation of the gum is an affection of consider- 
able importance, both on account of its sudden occurrenc' 
also, because it is liable to assume a diphtheritic charact 

Steinbergerf describes the occurrence of the malady as fol- 
lows : "In the first stage, the edge of the gum ie I with 
a whitish, gray, structureless, membraniform exudation, 
half a line in thickness, which may be detached in flakes. The 
mucous membrane, deprived of its epithelium, is slightly Bwollen, 
tender to the touch, and bleeds easily. Generally the exudation 
first appears upon the outer side, that is upon the margin of the 
gum of the lower jaw which faces towards the lips and el 
and frequently within the limits of the lower incisors, whence it 
spreads gradually over the whole anterior, and also the posterior 
margin which faces the tongue. It is a rare occurrence for it 
to attack the edges of the gums of the upper and lower jaw at 
the same time. 

"The exudation takes place very rapidly, often in a few h 
not infrequently during the night, and is accompanied by ■ 
painful sensation which the patient describe- as a drag 
pain, and this is increased if the patient remains in \ 
localities, or in bed. There is only slight febrile movement ; 
frequently it is scarcely perceptible. The cervical -lands of the 
affected side are swollen. 

"The exudation degenerates verv rapidly into an offei.^ 
sanious mass, so that the affection becomes manifest from the 



* Quar. Jour, of Dental Science, 1857 

f Croupose Entzundung des Zahnfleischrandes and ibre Folgen : d, 
Vierteljuhresschr. f. Zuhnheilk.. 1861. 



GUMS. 197 

patient's breath, even at a distance of several paces. The de- 
composed matter dips down, especially in the lower jaw, between 
the gums and the tooth, towards the root-membrane, which be- 
comes inflamed and finally is destroyed by the corroding sanious 
matter. The teeth are loosened and fall out, or may readily be 
removed. Subsequently the bone, from the imbibition of the 
sanious matter, becomes necrosed, without, however, at least in 
most cases, the occurrence of any swelling, showing that the 
necrosis originates from the alveolar cells and not from the peri- 
osteum of the jaw. 

"In the upper jaw, as a rule, the destructive process is not 
so extensive, in consequence of the ready escape of the purulent 
fluid. 

" If the inflammatory process leads to the death of the gum 
and the facial wall of the alveolar process (in other words, if a 
diphtheritic slough is formed), the necrosed portions of the bone 
exfoliate, and in children the dental germs are exposed. 

" Children are more frequently the subjects of the latter 
affection than adults, and those children particularly who have 
been reduced by scarlet fever, measles, and typhus. Still it 
also attacks healthy, robust persons. 

" The predisposing cause, in most cases, is exposure in a cold, 
damp dwelling, or to a cold, damp draught of air or excessive 
exposure to moisture and cold in travelling and hunting. The 
disease acquires a contagious character in hospitals for children. 

" The duration of the disease depends upon its intensity and 
extent, the general health of the patient, and external circum- 
stances. The more mild cases terminate in eight to fourteen 
days, and the more severe ones often last several months." 

Since the croupous inflammation, which has been described, 
often spreads to a considerable distance in the mucous membrane 
of the oral cavity, consequently attacks portions beyond its 
original seat, the gums, it is called by the general term stomatitis, 
and from the fact that it is associated with ulceration, Taupin* 
called it stomatitis ulcero-membranacea, and maintains that it is 
entirely distinct from diphtheritis. Distinguished writers, on 
the other hand, admit a transition from croup into diphtheritis. 

* Barthez and Kiliiet. Diseases of Children. 



J98 INFLAMMATIONS. 

^Phlegmonous inflammation of the gums involves both the 
corium and the submucous connective tissue, and is attended by 
considerable swelling and redness. 

Under this head may be classed the series of cases which 
Pye Smith* collected, and to which he gave the name stomatitis 
hsemorrhagica. The accession is sudden and without any febrile 
movement; the oral mucous membrane, especially that of the 
gums, becomes swollen without any participation on the pi 
the neighboring mucous membrane, the fan <1 mucous 

membrane, and larynx. Ulceration occurs in Bmall, shallow, 
} 7 ellowish spots, or is in the form of a large, phagedenic ulcer. 
Actual necrosis of the osseous substance may ensue. The in- 
tervening mucous membrane is always tumid, 
sitive, and easily bleeds. Recovery is very slow. '] 
was observed in well-nourished, otherwise healthy . who 

presented no indications of scorbutus or syphilis. 

Suppurative (abscedirend) inflamm 3 in a 

circumscribed formation of pus. an abe which 

latter usually opens externally, but sometimes andc 
sorption. Its course depends upon the causes to which it owes 
its origin. If it is produced by a mechanical cause, Buch as 
compression, contusion or laceration, it heals directly, with the 
occurrence of suppuration. If the suppuration n m an 

inflammation of the root-membrane, in connection with c 
it disappears immediately with the removal of the inflammation 
of the root-membrane, and if the latter assumes a chronic char- 
acter, the inflammatory irritation becomes extended to the gums 
and a fistulous track is formed, which opens externally 
the surface of the gum, where it presents indurate while 

the other extremity communicates with the Buppurat 
membrane, or maxillary periosteum, or with an al ithin 

the bone (Atlas, Fig. 118). The fistula evident] 
expected to heal until after the removal of the causes which 
give rise to the irritation. 

Acute or inflammatory oedema of the -urns is accompanied bv 
a considerable, pale tumefaction and great tension, and 



Virchow's Archiv., 1870: zur Gin-: 



DISEASES OCCASIONED BY THE FIRST DENTITION. 199 

quently is developed very rapidly by the action of mechanical 
or chemical irritants. 

Gangrene of the mouth {noma) also attacks the gums, which 
become decomposed into a gangrenous slough or sanies in which 
float the necrotic fringes. As is well known, if the gangrene 
attacks the deeper parts, the maxillary periosteum and the root- 
membrane are destroyed, and the patients (who usually are 
weak, badly-nourished children, living in dark, low, cold, and 
moist rooms), lose the incisors, canines, or bicuspids: portions 
of the bones become denuded and necrosed and, sometimes, the 
greater portion of the upper or lower jaw is log 

Diseases occasioned by the First Dentition. — It is well 
known that, with children born of healthy parents and whose 
external surroundings in life are not detrimental, teething is 
unattended by morbid phenomena which latter, however, make 
their appearance in children of unhealthy parents, or in those 
who are subject to the influences of obnoxious external agencies. 
While abnormal dentition may, perhaps, have been over-esti- 
mated by the physicians of former days, it is, on the other hand, 
sometimes too little regarded, indeed, even disregarded entirely 
by those of recent times, as a cause of affections of the nervous 
system, intestinal tract, respiratory organs, &c. Up to the 
present time, as far as I know, no one has yet made the en- 
deavor, which it is hoped will be made, to establish first of all 
an anatomical basis for abnormal dentition, by its pathologico- 
anatomical study. Physicians, as a general rule, are not fa- 
miliar enough with the process of dentition, ami dentists are 
not disposed, nor do they have the opportunity of prosecuting 
that study to any great extent. 

Fox, and with him a large number of English dentists, having 
in mind the morbid processes consequent upon difficult denti- 
tion, attached great importance to lancing the gums. " If the 
nurse," he says, "be attentive, she will notice that the child 
does not take the nipple with the same degree of force as usual, 
or holds it but a short time, and soon lets it go ; the gums feel 
hot and are redder than usual; the cheeks appear flushed, the 

* Barthez and Rilliet, vol. ii. 



200 INFLAMMATIONS. 

eyes look heavy, and the child is uneasy. When these symp- 
toms appear, the mouth should be examined and if there be any 
fulness of the gums, or they have the appearance of inflamma- 
tion, they should be lanced at that part. The order in which 
the teeth appear should always be kept in mind, and then there 
will be little probability of mistake, as to the spot where the 
cause of irritation is seated. To delicate children there is 
often danger attending the cutting of the canine- ami first 
molars, since these teeth advance in growth almost at the 
time, so that there are eight teeth making pressure upon the 
gums at the same time." 

According to Trousseau,* the swelling of the gums is n 
arching produced by the tooth beneath, but is due rather to the 
inflammation, and he adduces in support of his assertion, the 
fact that this turgescence occurs and disappears again, without 
the emergence of the tooth through the gum : direct experi- 
ment also confirms this view, for if a needle be inserted into the 
swollen gum, it is found to be three to four millimetres in thick- 
ness, from the surface down to the tooth. He found that the 
inflammation of the gum was always much more marked around 
the upper incisors, than around the lower ones. Troi 
does not coincide with the older physicians, in the opinion that 
teething is the cause of most of the diseases of infancy, and 
states that the local condition plays merely an a< part 

The painful swelling of the gum and the toothache give r 
various symptoms, particularly to flushing of the c fixa- 

tion, fever, agitation, and likewise to a few nervous sym] 
He doubts, however, that the diarrhoea is the secondary i 
of the pain, and remarks that diseases which occur during the 
process of dentition, such as broncho-pneumonia, pnenn 
and enteritis, are always more severe and dangerous, and further 
that among all the methods of local treatment, lancing the 
gum is by far most in favor, but it surely merits no recommen- 
dation. 

Inflammatory swellings of the gums, attending the eruption 
of the milk teeth, may assume a very alarming character. - In 



Barthez and Eilliet. vol. i. 



DISEASES OCCASIONED BY THE SECOND DENTITION. 201 

some, fortunately rare cases," says 0. Weber,* " the inflamma- 
tion may lead to a periostitis of the jaw, particularly of the 
upper jaw, which, if it be not treated very carefully, may give 
rise to gangrenous destruction similar to noma. In such cases, 
the cheek becomes swollen, then cedematous, and later acquires 
a phlegmonous condition. The eyelids assume a puffy appear- 
ance, the whole face becomes swollen and tense, and a careless 
physician might regard the case as one of erysipelas. If the 
condition of the teeth is not recognized, and exit is not given to 
the pus already formed beneath the periosteum, by free inci- 
sions, the cheek may become gangrenous and the jaw necrosed 
and destroyed. It is unnecessary to state that this condition is 
attended with high fever. In one case of this kind in which gan- 
grene was imminent, I preserved the life and the face of a child 
only by general incisions at various parts, since the suppuration 
had advanced already to the region beneath the orbits and 
beyond the zygoma." This all goes to show that inflammations 
of the gums during the eruption of the milk teeth are to be 
watched with the greatest care, and we must not assent to the 
nihilistic doctrine (Nihilismus), in respect of the influence of 
difficult teething upon the infantile organism (compare Neu- 
roses). 

Diseases occasioned by the Second Dentition. — The 
eruption of the wisdom teeth not infrequently gives rise to mor- 
bid phenomena which, as Hunter has observed, are more local- 
ized, while in the first dentition they are apt to be more general 
than local. The diseases! comprise, 1, neuralgic affections of 
the facial and temporal nerves, occasionally of an intermittent 
type; 2, a very obstinate cough like hooping-cough; the par- 
oxysms are shorter and the prolonged inspiration is wanting ; 
3, very obstinate attacks of dysenteric diarrhoea, which continue 
five, six, even seven months, while the general condition and 
appetite are not disturbed. 

The difficult eruption of the wisdom teeth is due, in most 
cases, to their faulty position, together with insufficient length 

* Handbuch der allg. und spec. Chirurgie redig. v. Pitha und Billroth, 
Bd. iii, p. 234. 

f Barthez and Rilliet, vol. i. 



202 



INFLAMMATIONS, 



of the jaws, and especially of the lower jaw, or to some affection 
of the adjacent tooth. For example, Fig. 76 represents an ex 



Fig. 76.* 




tensively carious, lower second molar, on the left Bide, the 
alveolus of which, together with the surrounding portion of the 
jaw, was infiltrated with sanious matter. The pathological pro- 
cess commenced with an inflammation of the periosteum of the 
root which was followed by periostitis and the formal 
minutely porous osteophyte, and necrosis of the contiguous 
tions of the jaw. The eruption of the wisdom tooth, which waa 
inclined somewhat anteriorly, had commenced, and the an I 
segment of the alveolus was involved in the sanious ulceration. 
If, in this case, the second carious molar had been extracted at 
the proper time, the consecutive inflammatory pi would 

not have been so extensive. 

A notable disturbance is presented at the time of the eruption 
of the wisdom teeth, if ulceration of the alveolar pro 



* Fig. 76 shows a circumscribed necrosis upon the lingual wall of tl 
lower maxillary arch, corresponding to the carious second mo':, 
a finely porous osteophyte-formation upon the adjacent portion ol' the i 
lary wall. The wisdom tooth (a) has just made its appearance. T: 
colored, necrosed portion is sharply defined, and adjacent to it i> 
thin finely-porous osteophyte, which spreads anteriorly upon tl 
surface as far as (6), and posteriorly nearly to the articular coiuh 
lous opening was formed upon the facial wall of the jaw beneath the p. - 
root of the second molar. The porous osteophyte extends anteriorly 
this surface as far as the mental foramen and posteriorly to th< 
process. Natural size. 



DISEASES OCCASIONED BY THE SECOND DENTITION. 203 

subsequent dislocation of the teeth have ensued (Fig. 77). In 
this case, it is very probable that a retarded eruption of the 

Fig. 77.* 




* Fig. 77 shows the tooth, on the left side of the upper and lower jaws, 
bent forwards, in consequence of a partial destruction of the alveolar pro- 
cesses, probably the result of a diphtheritic periostitis, which was caused by 
the eruption of the deeply-imbedded wisdom teeth on the left side. (For 
the specimen from the Anatom. Museum, the author is indebted to Dr. 
Friedlowski.) The two central incisors and the left lateral of the upper 
jaw are bent upwards into a nearly horizontal position; the left upper 
canine and the two bicuspids are inclined to a less degree ; the first molar, 
on the left side, occupies its normal position ; the second is displaced towards 
the tongue and is covered with a deposit of tartar (a) ; the emergent wisdom 
tooth (b) has a marked forward inclination and is located to the outside of 
and behind the second molar. In the lower jaw, the coronal borders of the 
central incisors are separated by an interval of eighteen millimetres from 
each other, the result of an ulcerative inflammation of the alveolar process ; 
notwithstanding this notable gap, no tooth has fallen out; the incisors, 
canine, and two bicuspids of the left lower jaw, are inclined towards the 
lips, and the second bicuspid (c) is displaced to the front of the buccal surface 
of the first molar ; the second molar is bent towards the tongue ; the wisdom 
tooth has a horizontal position with its masticating surface directed ob- 
liquely towards the tongue. The bone around the latter tooth, like that 
upon the maxillary tuberosity of the upper jaw, is destroyed, and to such an 
extent, that the roots are exposed for the most part. The wisdom teeth, 
upon the right side, occupy normal positions within the dental ranges ; the 



204 INFLAMMATIONS. 

wisdom teeth, on the left side, gave rise to an inflammation of 
the gums, which extended upon the facial surface of the latter, 
along the upper and under dental arches, involved the periosteum 
of the facial walls of the alveolar processes and destroyed 
walls and, also, the anterior walls of the dental sockets. The 
osseous substance surrounding the wisdom teeth was necr 
a result of the periostitis. The lingual walls of the alveolar 
processes were not, but, as may be seen, the margin of the in- 
cisive fossa on the frontal process of the upper jaw, and the 
anterior borders of the ascending coronoid pi the lower 

jaw, were involved in the ulcerative process. The teeth, de- 
prived of the support afforded by the facial walls of the alveolar 
processes and jaws, became very much inclined. Tin- 
shows what may be the results of neglect and ignorance. If 
the wisdom teeth are deeply imbedded in an oblique position, 
they may, during their eruption, give rise to fistul- 
A case came under the observation of H eider, in which r< 
tion of the single root with exposure of the pulp-cavity of the 
second molar occurred in connection with a very marked forward 
inclination of an erupted wisdom tooth. lie also saw another 
case, which presented resorption of the root of a lateral, perma- 
nent incisor, in connection with the retarded eruption <»f an ab- 
normally located canine.f Wisdom teeth of the lower jaw, which 
lie in a horizontal or oblique position, may also be the foundation 
of the occurrence of tumors in the osseous Bubstanc 

Root-Membrane.— Inflammation of the periosteum of the 
root is of especial importance, not merely on account of it- fre- 
quent occurrence, but also from its tendency to- invade the 
neighboring tissues; its importance, however, was not fully 
estimated until within the last decades of this century. 
Hunter considered it to be an inflammation of the socket oi' the 



teeth of this side, in part, are notably affected by curies. There remains, 
finally, to be mentioned, an accumulation of tartar upon the lingual surfaces 
of ^the dental crowns on the left side. Two-thirds natural - 

* Durand. Ill effects produced by the eruption of a wisdom tooth, in 
Part Dentaire, Paris, I860. 

f Deutsche Viertelj. f. Z., 1862. 

% Dental Register, 1869. Affections of the Jaw. Waterman. 



ROOT -MEMBRANE. 205 

tooth, and described it as "gum boil," which is still its popular 
name. Lefoulon (1841) distinguished it as periodontitis ; Lin- 
derer (1842), as an inflammation of the external dental mem- 
brane. We are indebted to Albrecht* for a monograph upon 
the subject. 

With reference to the extent, there is distinguished a localized, 
limited to one tooth or perhaps to one root of a tooth with mul- 
tiple roots, and general inflammation which spreads over a whole 
row of teeth of the upper or lower jaw, as with phosphornecrosis, 
for instance, or hydrargyriasis, and diphtheritic inflammation of 
the gums. It is further separable into a primary and secondary, 
an acute and chronic form. 

Bearing in mind the anatomical relations of the root-mem- 
brane, its connection with the vessels and nerves which enter 
the pulp, with the alveolus and gums, and with the periosteum 
and bony substance of the jaw, the phenomena that accompany 
the inflammation are readily accounted for. Although these 
make their appearance in regular succession, it is customary, 
for the sake of greater clearness, to divide them into stages as 
follows : 

1. Inflammatory thickening, with hyperemia and commencing 
proliferation of the elementary organs of the connective tissue, 
which takes place both in the parenchyma of the root-membrane 
and also in the fibrous sheaths .of the bloodvessels and nerves. 
Groups of nuclei, presenting the familiar forms which result 
from their division and inclosed within a protoplasm, become 
apparent and occasion faint, cloudy spots. 

2. In the second stage, the cloudiness increases and pervades 
the entire thickened root-membrane which acquires a gray-red- 
dish appearance. The groups of proliferating elements assume 
larger proportions; the nuclei and also the investing protoplasm 
acquire a molecular cloudiness; here and there, they present a 
shrivelled appearance, vessels and nerves become unrecognizable, 
the basis-substance, the intercellular tissue is displaced, for the 
most part, by the products of the proliferation, and supplanted 
by fat-granules. In many cases, the inflammatory process ter- 
minates with this proliferation. 

* Die Krankheiten der Wurzelhaut der Znhne, 1860. 



205 INFLAMMATIONS. 

3«. In the third stage suppuration takes place, and the same 
series of pathological phenomena ensue, as have been descril 
above in connection with the suppurating pulp (Atlas, Fig. 8 

In very acute cases the proliferation of the elemental 
takes place very rapidly, and their degeneration ensues imme- 
diately. 

The clinical history of the first stage, in the acute fori; 
given by Heider, is as follows: Sensitiveness of the root in- 
volved, which at first is not continuous and is characterize- 
a dull, undefined sensation of oppression in the tooth. Aft 
this has continued some time (for days or hour-, aninteimpl 
pains occur in the tooth, which are notably increased by contact 
with anything, especially by attempts to chew, by simply 
closing the mouth, or by percussing the tooth, particularly in 
the direction of the root, The pains are also intensified by the 
local application of warmth and by general heating of the body, 
by active movements, the horizontal position, and spirit i 
drinks. There is now developed a distinct Bensation, as if the 
tooth was increasing in length and becoming loose. The former 
is subjective merely, the latter, evidently, is objective a 1 ^ 
the affected tooth can be moved with the application of b 
force. These same symptoms are also presented, 
gree, by the two teeth adjacent to the one originally 

Then occur the phenomena presented by the gums, which, at 
the corresponding portions, become more red. more hot to the 
touch, swollen and sensitive to pressure with the finger, particu- 
larly in the vicinity of the apex of the root. 

The secretion of saliva is augmented, and increased heat and 
redness is observed upon the affected side. With irritable per- 
sons, there is general indisposition, a coated tongue, loss of ap- 
petite, and sometimes febrile movement. 

These symptoms oftentimes continue only a few hours, and 
again may last for days, and then all at once become more 
marked. The pains become more intense, almost intolerable : 
the patient can no longer endure contact of anything with the 
tooth, not even of the tongue : the mouth cannot be closed : the 
tooth apparently increases in length, since it is raised per- 
ceptibly above the level of the dental range, especially when 



ROOT-MEMBRANE. 207 

the tooth has several roots ; there is a corresponding increase 
in its mobility ; the contact of anything hot cannot be borne, 
and the patient is unable to take solid, cooked food, or even 
tepid liquids ; cold local applications produce a temporary relief, 
but the pain returns in a more severe form. At the same time 
the swelling of the gums increases considerably and also extends 
to the mucous membrane of the cheek, and to the integument 
of the face, which becomes cedematous as the disease progresses. 
When the front teeth are affected, the lips become swollen and 
produce a marked disfigurement ; their mucous membrane be- 
comes elevated into bulla?, and the ala of the nose on the cor- 
responding side is swollen. When the bicuspids and molars of 
the upper jaw are attacked, the lower eyelid becomes cedema- 
tous, and this condition may increase so as to produce a complete 
closure of the eye. With the affection of the teeth of the lower 
jaw, the oedema spreads downwards upon the neck, principally, 
and may, especially when the wisdom teeth are involved, extend 
to the mucous membrane of the soft palate, and, if not checked, 
oedema of the glottis may ensue. The neighboring glands, par- 
otid and sublingual, likewise, are swollen, as might be expected. 
Accompanying these symptoms, the oral cavity becomes quite 
hot, the tongue thickly coated ; an extremely offensive, purulent 
odor is emitted from the mouth, and the mucous secretion be- 
comes very adhesive. At this stage, there is an accession of 
general symptoms, including more or less notable febrile move- 
ment, general indisposition, headache, thirst, and even delirium 
with very irritable, plethoric individuals. 

With the latter symptoms, suppuration occurs, while the pain 
loses its acute character and assumes a more dull and beating 
form. The portion of the gum adjacent to the tooth, which 
was primarily affected, swells considerably and projects in the 
form of a fold. The tumor, which now has attained its greatest 
dimensions, becomes soft and fluctuating and in time presents 
a yellowish spot, where the pus becomes perceptible and makes 
its exit, if the tumor is left to itself. As soon as the pus is 
evacuated, there is a very rapid diminution in the intensity of 
all the symptoms ; the oedema disappears in a few hours, and 
after the lapse of about twenty-four hours, the swelling is re- 



903 INFLAMMATIONS. 

stricted to the locality of the tooth originally affected. If the 
suppuration diminishes considerably during the Bucee 
then the tooth resumes its original position and firmness, and 
becomes serviceable again ; on the other hand, circumstances 
may give rise to additional suppuration, the 1 S of the 

tooth and the discoloration increase, and finally its death 
and it is lost. The average duration of the acute process. Bach 
as has been described, is seven to eight d 

• The suppuration is reduced, in the course of time, to ■ mini- 
mum, where it is kept up for a considerable period, until the 
small opening in the membrane bee Q of 

which is then denoted by a small nodule. Relapses are oc 
sioned by slight causes, among which may I 
ure of the feet to cold, in particular, overheat 
drinks, &c. A small vesicle is formed at the original 
disease which becomes filled with pus. and is raptured by the 
movements in mastication and evacuated. Usually the 
closes after this, and in a few days again a small postal 
formed at the same place which runs the Bam the 

first. Sometimes the latter process is repeated for 
without troubling the patient, and is due to a chronic inflam- 
mation of the root-membrane. 

The clinical history of chronic inflammation com] 
following most prominent symptoms: An w. 
painful sensation, referred to the root, which is ii by 

pressure upon the tooth and by chewing. The gum of the 
affected tooth is reddened, and pressure in the vicinity of the 
apex of the root gives rise to pain. The 
pears to be longer than usual and loose, which, 
merely an imaginary sensation on the part of the patient. A: 
first, these symptoms are altogether of such an ill-defined nature, 
that they easily escape the notice of less observant pati- 
who are not made aware of the affection until, in the c 
time, either severe pains are felt at the apex of th< r the 

edge of the gum becomes tumid, and a yellowish nun 
out between the latter and the neck of the tooth. 1 
quence of detrimental agencies, the latter process pr g sees, 
and intermittent, inflammatory pains are develop* ally 



ROOT-MEMBRANE. 209 

when the inflammation is located at the apex of the root. The 
redness of the gum increases, its margins become swollen, the 
outer wall of the alveolus is very sensitive to pressure, the tooth 
cannot be employed in chewing, becomes loose and, apparently, 
increased in length. Frequent remissions occur, but the same 
process is repeated after longer or shorter intervals*, and ends 
with the loss of the tooth. The process continues, throughout, 
a local one and the general system is not disturbed. This con- 
dition of things is observed most frequently in well-nourished, 
vigorous, middle-aged persons. 

While, in the acute form, the proliferation of the cellular 
elements of the connective tissue is arrested in the embryonic 
stage of the latter and a partial degeneration is induced by the 
luxuriance of the cell-production, in the chronic inflammation 
a higher grade of organization is attained, but under favorable 
conditions, the chronic may be changed into the acute form. 

The periosteum of the root presents a gradual increase in 
thickness towards the apex of the root, its tissue is compact, its 
outer surface not infrequently like felt and, sometimes, highly 
vascular (Atlas, Fig. 122). Besides the roundish or ovoid con- 
nective-tissue cells, rows of spindle-shaped, elongated cells, also, 
are met with ; later in the progress of the affection, wavy, 
curled bundles of connective tissue appear in the basis-sub- 
stance, between which rows of roundish cells are imbedded. In 
such localities the nerves and vessels undergo a perceptible 
wasting away, while the larger bloodvessels are expanded. 
The proliferating connective tissue undergoes a partial involu- 
tion [retrograde metamorphosis] which is manifested by the 
appearance of fat-granules_, partly within the protoplasm of 
the cells themselves, and partly in the intermediate substance ; 
but, nevertheless, germs of proliferation may persist, which will 
be excited to renewed activity with the occurrence of an irrita- 
tion. If the degenerative process goes on to the transformation 
of the tissue into a minutely molecular mass (detritus), which 
frequently occurs without any perceptible suppuration, it always 
displays itself first on the outer zone of the root-membrane 
(Atlas, Fig. 123). It is self-evident, that the connection of the 
root-membrane with the alveolus, at the latter locality, becomes 

14 



210 INFLAMMATIONS. 

destroyed, and the tooth is loosened in its socket by this pro- 
cess. 

Inflammation of the closed extremity of the periosteum of 
the root, with suppuration in the inner layers of tissue, - 
times occurs, giving rise to the formation of a spherical sac of 
pus, which may attain the size of a small pea. A 
known, it is not an uncommon occurrence, when the affected 
tooth is extracted, to find the sac unbroken and attached like a 
berry to the apex of the root. According to Iluhn 
this kind very rarely result from an acute, but almost invariably 
from a chronic inflammation. 

The fibrous envelope of the pus sac (in subacute e;i 
forms a thin, transparent wall, which is traversed by a network 
of bloodvessels and incloses a distinctly fluctuating, purulent 
mass, mixed with more or less blood. In chronic 
velope is thick, less smooth upon its outer surface, and fluctua- 
tion is less distinct. In the latter cases, it is composed of three 
separate layers; a, an external, thicker, more resistant 
in which cells of an oblong shape, imbedded in a fibrous stroma, 
predominate; b, a middle, less firm, more succulent layer, 
containing, principally, rounded, nucleated cells which arc in- 
serted into a felted mass of filaments, in parallel rows or in 
irregular clusters; c, an internal layer, a sort of granulation 
tissue, with the pus adherent to it. The thicker the wall of the 
sac, the less recognizable is the central focus of Buppura 
and in that case, cross-sections present a network of branching 
trabecule of connective tissue, inclosing groups of stellate 
nective-tissue cells. In old purulent deposits, a disii 
mass containing fat-granules and eholesterin, is accumulated a: 
the centre of the sac. 

Chronic inflammation also gives rise to hypertrophy and 
tumors of the root-membrane and, sometimes, 'leads to hyper- 
trophy or exostosis of the cement. 

That portion of the root-membrane, which is in relation with 
the submucous connective tissue of the -urns, appears to be at- 
tacked secondarily, in most cases, in consequence of the exten- 
sion of the disease either from the inflamed closed extremity of 
the root-membrane or from the inflamed -urns. In these 



ROOT -MEMBRANE. 211 

the gum becomes detached from the neck of the tooth, and pres- 
sure upon the alveolus forces out a puriform fluid. This condi- 
tion, which has been described as pyorrhoea alveolaris, particu- 
larly by French writers,* results, without notable pain, in the 
loss of the affected tooth. It also attacks whole sets of teeth in 
one or another jaw, and is met with, more frequently, in persons 
of middle age, and may last several months, even years. At 
last all the teeth in the jaw become loose and are lost. While 
the latter effect is being produced, the inflammatory symptoms 
in the gums often disappear apparently; but if pressure be made 
with the finger along the root, towards the neck of the tooth, a 
tenacious gelatinous fluid oozes out, indicating the existence of 
the inflammatory affection. The latter secretion invariably ap- 
pears, first of all, upon the facial segment of the gums, but later 
is found also upon the lingual. Albrecht is of the opinion, that 
the pressure of the tongue and its constant sucking action upon 
the lingual surfaces of the alveolar processes, prevent the accu- 
mulation of the purulent matter, and that pressure by the finger 
upon the latter surfaces does not give vent to a puriform fluid, 
unless the affection is very far advanced. In these cases, then, 
we have to do, first of all, with a catarrhal inflammation of the 
gum, which afterwards extends to the root-membrane. 

In very acute cases the inflamed root-membrane degenerates 
into an unctuous, fetid, ichorous, pulpy covering of the surface 
of the root, i. e., it undergoes gangrenous metamorphosis. In 
such cases we find a clouded, dirty-yellow or brownish-yellow, 
granular mass (detritus), containing, usually, shrivelled nuclei 
which are barely recognizable, and numberless rod- shaped, 
slender, occasionally undulating bodies (Bacteria) which were 
regarded by Pasteur as a putrefactive ferment. 

If we bear in mind the intimate connection of the root-mem- 
brane with the vessels and nerves of the pulp, which has been 
referred to repeatedly, also with bloodvessels which enter from, 
and return through the alveolar walls, and with nerves coming 
from the foramen in the alveolus and the intra-alveolar canal, 
it is easy to understand that an inflammatory condition of the 

* Toirac. and subsequently Desirabode. 



212 INFLAMMATIONS. 

root-membrane cannot persist without implicating the adjacent 
structures. 

The changes in the hard tissues of the root, which occur chiefly 
with chronic suppurating inflammation of the periosteum of the 
root, consist in necrosis and resorption, according to the nature 
of the tissue. If the superficial cement be not die . dull, 

whitish, indistinct spots may be observed, sometimes, incorpo- 
rated in it. If these are cut out in thin plates and examined with 
transmitted light, they present a clouded dirty . ni>h- 

yellow, and from this to a black-brown color. The bone-cor- 
puscles become less discernible in the mac rency 
diminishes ; the intercorpuscular Bubstanc formed chiefly 
into a minutely granular mass, and frequently has a foramil 
appearance. 

In consequence of resorption following suppuration, the 
surface of the root becomes rough, sometin 
roded, covered with irregular excavations 

lowed out like a funnel at the part c th the 

entrance to the canal, or sharpened to a point, like a needle. 
The histological appearances produced by the 
tion are displayed in a manner similar to those which were ob- 
served in the resorption of the roots of the milk tt . there 
are circumscribed depressions upon the outer surface of the 
cement, which are made up of groups of 

shallow, cup-shaped indentations. In the ridge-like elevations 
which bound the excavations, well-preserved bone-c 
are to be found, while they become gradually 
the deeper portions. Necrosis of the cement not infrequently 
is associated with resorption, in which c 
directions perpendicular to the surface of the 
of a dark color and with obscurely defined ma D the 

excavations produced by resorption. 

If the cement is entirely destroyed | usurirn. here and there, 
by the suppuration, the dentine becomes similarly affected and 
acquires a roughened or corroded appearance. If the atf 
portions are examined carefully, they will be found to be ir 
larly notched with numerous cup-shaped excavations with sharp 
outlines, which sink into the dentinal substance, are 



ETIOLOGY OF INFLAMMATION OF ROOT -MEMBRANE. 213 

together, frequently into groups, and contain the corroding pus. 
The adjacent portions of the dentine, with the tubules running 
from them, retain their normal transparency. The indentations 
themselves are lined with a molecular mass which, frequently, is 
impregnated with a yellow, or brownish-yellow coloring matter; 
their projecting margins are delicately notched ; their exposed 
surfaces are occupied by transversely and obliquely-divided den- 
tinal tubules (Atlas, Fig. 115). There are, consequently, no 
indications of a vital acton on the part of the dentine. The 
theories advanced to explain the manner in which the excava- 
tions are produced by resorption are mere suppositions ; they 
may be regarded as induced either by the activity of the pus- 
corpuscles, or by a fermentation process; with regard to the 
former, it is conceivable, that the amoeboid movements of the 
corpuscles might wear away the dental substances; in the latter 
case, the generation of an organic acid might be assumed. In 
chronic cases, the eroded portions are covered by a thin mem- 
brane of connective tissue or by a layer of granulation tissue. 

Sometimes, on the other hand, the inflammation spreads from 
the root-membrane to the socket of the tooth; when this occurs, 
the canals of the latter in the vicinity of the focus of suppura- 
tion become expanded ; excavations, in the form of pits and 
grooves, are formed in it, and, finally, there ensues a partial 
resorption of the alveolus, which process is induced by the pro- 
liferation of the elementary organs of the connective tissue. 

Etiology of Inflammation of the Root-Membrane, — The most 
common origin is a pre-existing inflammation of the pulp which 
itself is produced by penetrating caries, in most cases. Hence 
the affection becomes a complicated one. The cause of the sub- 
sequent inflammation of the root-membrane is to be found, as 
has been observed before, in the direct transmission of the irri- 
tation from the inflamed nerves and vessels of the pulp to those 
of the periosteum of the root. If the pulp be irritated by a too 
early filling of a carious cavity, or if the escape of the pus from 
an inflamed and exposed pulp be prevented by filling, symptoms 
of the inflammmation of the root-membrane are very likely to 
occur, since the decomposing pus rises or sinks within the canal 



214 INFLAMMATIONS. 

of the root, and acts as a strong irritant upon the portion of the 
membrane at the extremity of the root. 

Persons who work in match-factories, where they are exposed 
to the fumes of phosphorus, are liable to be attacked with inflam- 
mation of the root-periosteum, if they have carious teeth. The 
affection always originates, asserts Albrecht, at a part where 
the fumes of phosphorus have access to the membranes covering 
the bone, and, in the mouth, the best opportunity for thifl 
is afforded by the diseased teeth in which the pulp-cavities have 
become exposed. The noxious element is carried to the part 
chiefly by the saliva which becomes saturated with the fun. 
is manifested even by the characteristic penetraL r that 

escapes from the mouth, by means of which alone a worker in 
phosphorus may be recognized ; further, by tli. 
which, on expiration, frequently becomes luminous in the dark. 
The pus of phosphornecrosis is said to contain a large amount 
of phosphorus, the truth of which assertion, however, Hoppe- 
Seyler considers very doubtful. The fumes themselri 
to exercise no destructive effects upon the hard dental tisf 
I have noticed merely a blue-gray tinge. Albrecht observed a 
faceted appearance upon the extremities of the roots, if the 
are retained for a considerable period. An hypertrophy of the 
cement appears not to take place, nor does a destruction of the 
cement layer occur, probably because the pro- 
producing a complete destruction of the root-membran 
quickly; the roots appear to him to be somewhat more trans- 
parent at their extremities, and of a horny character. 

The extension of the inflammation of the periosteum of the 
root of one tooth to that of the adjacent one is effected by means 
of the periosteum of the jaw, which becomes swollen conl 
raneously with the former and. like it, is destroyed, - absceded" 
(abscedirt). In cases, where the jaw contains no carious tooth, 
and still inflammation of the root-periosteum occurs, as an effect 
of the fumes of phosphorus, the saliva, impregnated with the 
latter, affects the gums primarily, and then the root-membrane. 

The inflammatory affections of the gums hereby induced spread 
also to the root-membrane; this occurs more frequently with the 
teeth of the lower jaw, because pus or sanious matter accumulates 



ETIOLOGY OF INFLAMMATION OF ROOT -MEMBRANE. 215 

more readily in the pouches formed by the gums of these teeth, 
and produces an irritation upon the root-membrane which is in 
immediate contact with the submucous connective tissue of the 
gums. Consequently the original cause of this inflammation of 
the root-membrane is the same with that of the inflammatory 
affection of the gums. 

Mercury, likewise, acts upon the root-membrane through the 
gums, and may even affect the whole set of teeth ; bat the teeth 
of the under jaw, which are bathed with the saliva, are the 
soonest, involved. The teeth are lifted out of their alveoli, with- 
out any special sensations of pain, in consequence of the swelling 
of the root-membrane, and, as the process advances, they become 
loosened so much that they are easily separated from the alveoli. 
The root-membrane is then found to be covered with a tenacious 
unctuous, viscid mass.* 

Mechanical causes, e. g., a kick or blow, dental operations 
which are not conducted with proper care, especially with per- 
sons who are very susceptible to injuries of any kind, a ligature 
around the neck of the tooth, foreign bodies which become forced 
into the pouches formed by the gums or into the root-canals of 
carious teeth, e. g., bits of toothpicks, stumps of teeth which 
have become fastened to the root, concussion of the jaw from a 
fall, &c, may give rise to an inflammation of the root-membrane 
and are more likely to do so, if the latter is in an irritated con- 
dition previously. Pressure in chewing, exerted in an abnormal 
direction upon one or another surface of the roots of an obliquely- 
located tooth by its antagonist, may irritate the root-membrane 
and lead to an inflammation. In a wisdom tooth, with its crown 
inclined anteriorly and impinging upon the second molar, the 
root-membrane is exposed to injury in consequence of the con- 
cussion occasioned during the act of mastication. Albrecht 
mentions a case, which came under his observation, of an in- 
flammation of the root-membrane of the milk molars, which was 

* Albrecht states, that several other substances may produce similar 
effects, but that it is not such a common occurrence with them as it is with 
mercury. Affections of the root-membrane have been observed following 
the use of preparations of gold, copper, arsenic, antimony, iodine, and the 
employment of digitalis and opium, castor and croton oil, and cantharides. 



216 INFLAMMATIONS. 

induced in consequence of the advance of the permanent bicus- 
pid's prior to the complete resorption of the roots of the milk 
teeth. 

In replantation of children's teeth which have been forced 
from their alveoli in surgical operations or separated from their 
alveoli, without any fracture of the same, by a kick, fall, or 
blow, it is well known, that they will become fixed under favor- 
able circumstances, more readily, to be sure, when the in* 
of time is short and the teeth remain attached to the gums. 
Transplantation of the teeth of different individuals, immediately 
after their extraction, as Hunter proposed, does nut, on the whole, 
furnish favorable results, since the roots of corresponding teeth, 
in different individuals, vary so much in thickness 
curvation ; consequently, the alveolus is either injured or in- 
completely filled, and the subsequent inflammatory pro< 
prevent the desired fixation. Mitscherlich* rel tancei 

of partially successful results from the implantation of 
teeth, in which cases the inserted tooth beconx 8 
osseous tissue which grows into the dentine from the maxillary 
surface. 

The root-membrane is subject, also, to a rhem 
which may be either primary or secondary: in th< 
it remains localized or spreads to the periosteum of tl 
is accompanied by other rheumatic symptoms. In tl 
case it extends from the periosteum of the jaw to that of the 
root, and involves the whole set of teeth. The pains have no 
special character, so that it is impossible to Bpeak 
rheumatic toothache. Almost always there arc on e un- 

sound teeth, whose diseased periosteal membranes exc 
secutive swelling of the maxillary periosteum with the Bym] 
of rheumatism. 

Alveolar Abscess.— When an abscess of the periosteum at 
the extremity of the root is left to itself, and there 
for the pus, either through the root-canal and I pulp- 

cavity or along the surface of the tooth to the margin of the 
gums, one side of the alveolus, particularly in debilitated per- 



Langenbeck's Archiv. lur Chirurgie, 186*. 



ALVEOLAR ABSCESS. 217 

sons, undergoes a complete resorption from the proliferation of 
the connective-tissue cells in the wall of the abscess or from the 
eroding pus ; that portion of the maxillary wall which incloses 
the alveolus, together with its periosteum, becomes involved 
within the limits of the abscess. A suppurating (" absceding") 
periostitis is produced, the subsequent progress of which is 
modified by the special local relations. 

It is not an infrequent occurrence for a purulent infiltration 
into the spongy, osseous tissue surrounding the alveoli to take 
place, and the more abundant this tissue is, the greater is the 
liability to the occurrence of infiltration. "When the necrotic 
pus has perforated the maxillary periosteum, it flows downwards 
from its own weight, in the loose connective tissue, unless its 
course is obstructed, when it seeks an exit in another direction, 
which is governed by the local anatomical relations. The fis- 
tulous track not infrequently attains a remarkable length and 
terminates in a fistulous ulcer upon the external integument, in 
the mucous membrane of the cavity of the mouth, or in some 
other cavity. The arrest of this affection, which lasts some- 
times for years, not infrequently endangers life and often is 
not fully recognized by physicians, can only be effected by 
operative interference, which is to be determined by a thorough 
examination of all the parts involved in the region of the oral 
cavity. 

An abscess, originating at the closed extremities of the root- 
membranes of the inchors of tin; upper jaiv, generally perfor- 
ates the anterior alveolar wall at a point corresponding to the 
apex of the root. The periosteal portion of the gums becomes 
conjointly involved, and a fistulous track is formed which opens 
in the outer cavity of the mouth upon the facial surface of the 
gum, and more or less below the level of the focus of suppura- 
tion. The pain ceases as' soon as an exit for the pus is afforded. 
The cavity of the abscess attains, on an average, half the size 
of a split pea, and is lined with a membraniform layer of con- 
nective tissue. In the skeleton, the former cavity of an abscess 
presents a sharp outline ; its rounded internal surface, tolerably 
smooth, presents indentations which result from the eroded can- 
celli (Atlas, Fig. 124). When the central incisors are affected, 



218 INFLAMMATIONS. 

the' incisive canal on the corresponding side, also, becotm 
volved, subsequent to the destruction of the inner alveolar wall. 
The cavity of the abscess sometimes, also, takes an upward c 
upon the incisors, and perforates the floor of the nasal cavity. 
The opening in the anterior segment of the - floor ac- 

quires the size of a lentil or pea. Not infrequently the pus- 
sac extends downwards and backwards in the direction of the 
inner cavity of the mouth, and occasions resorption of the thick 
osseous layer in the most anterior portion of the hard palal 
consequence of which, a round hole, sometimes, of considerable 
size, is formed. Within the pus-cavity, projects the rout of one 
or those of both, incisors (Atlas, Fig. 125). The D 
the hole, in the palatal process, are smooth, rounded or sharp 
at the edges, as if cut with a knife. Sometimes, it also hap- 
pens, that the same abscess spreads in all the tin -men- 
tioned directions, towards the labial, nasal, and palatal sin : 
and perforates the cortical, osseous layer-. A- a result of this, 
the outer (vestibulum oris) and inner cavities of the mouth, and 
the nasal cavity upon the affected side communicate with 
other by means of fistulous tracks (Atlas. I \* 
Several cases of aneurism of the superior palatii 
have been observed, which admonish us to be on our 
against making a too hasty diagnosis and opening an imaginary 
abscess. 

The upper canine teeth are less frequently the 
suppurative inflammation of the root-membrane. When they 
are attacked, the disease is, generally, an extension from the lat- 
eral incisor, or from the first bicuspid, and there are path..' 
specimens of these spreading abscesses in which whole r 
roots are exposed, by the melting away (Schmelaung) of the 
anterior or posterior maxillary wall. 

Sewillf reports a case of a fistulous opening at the inner 
canthus of the right eye of a child, ten yea i g There 

had been a constant purulent discharge from the openii 
some months, and, to all appearances, it resembled a lad. 



* Teirlink, Castle, Herapath. 

f Odontological Society of Great Britain. 



ALVEOLAR ABSCESS. 219 

fistula. The sound was passed into the opening, and it extended 
as far as the canine tooth, which was discolored. This tooth 
was extracted and recovery speedily ensued. 

Alveolar abscesses upon the upper bicuspids and molars com- 
monly open upon the facial wall of the jaw, and it is not un- 
common to find the extremities of several roots projecting into 
the cavity of the same abscess. Sometimes, the cortical layer 
of the external maxillary wall is raised in the form of a pro- 
jecting wall, with a sharp edge, towards the cavity of the ab- 
scess (Atlas, Fig. 127). Occasionally, the lingual portion of 
the alveolar process presents a breach in the osseous substance 
which is bounded by sharp edges and corresponds with the par- 
tially denuded, carious roots of the molars. 

After the pus has undermined or perforated the periosteum 
of the jaw, it forces its way along the connective-tissue sheaths 
of the muscles and, not infrequently, escapes externally through 
the integument (buccal fistula), or penetrates the parotid gland 
and produces a salivary fistula. If the extremities of the roots 
project far into the antrum, the pus may perforate the mucous 
membrane and escape into the cavity or, if the teeth or roots 
are extracted, give rise to a fistula of the antrum, which is dis- 
played in the skeleton as a funnel-shaped depression with a 
corresponding opening in the floor of the cavity. The maxil- 
lary tuberosity frequently becomes infiltrated with the pus from 
the abscesses of- the roots of the upper wisdom teeth (Atlas, 
Fig. 139). J. A. Salter* relates the following grossly neglected 
case of inflammation of the root-membrane of an upper molar. 
A female, twenty-four years of age, was attacked with a severe 
toothache, referred to the first upper molar on the right side, 
the pain being accompanied by an extensive swelling of the 
same side of the face and attended with intense suffering. The 
eyeball became protruded, and she soon noticed, that she was 
unable to see with that eye. In a short time after this, the ab- 
scess pointed in the vicinity of the inner, and later near the 
outer canthus, and a large quantity of pus escaped. The open- 
ings then closed again and the general symptoms remained the 

* Medical Times, 18G2. 



220 INFLAMMATIONS. 

same. The latter condition continued three weeks. On ad- 
mittance to the hospital, the patient presented a repulsive dis- 
figurement of the face, oedema of the lids, livid skin. The first 
upper molar on the right side, together with other carious teeth, 
were removed, and the antrum could be reached through the 
partially absorbed alveolus of the first tooth. There was con- 
siderable necrosed bone, including a large portion of the inner 
and outer walls of the orbit, which was separated. The mo- 
bility of the iris was restored, but not vision. The author re- 
lates an analogous case from the practice of Pollock, where 
there was an intense inflammation of the whole maxillary 
region, occasioned by a carious tooth; it involved also the or- 
gans in the orbit. The inflammation yielded after the extrac- 
tion of the tooth, but the power of sight wi 

C. Williams* reports a case of an alveolar i\ rhich 

occurred subsequent to the extraction of an upper molar and 
opened upon the inferior margin of the orbit, just beneath the 
outer commissure of the eyelids. The pns made i 
the zygomatic process along the temporal muscle, its escape in 
the temporal region being prevented by the latter and the 
strong fascia investing it; it made its way through tl - 
maxillary fissure into the outer and lower portion of the orbits, 
and escaped by means of a fistulous opening. There was 
marked exophthalmia of the left eye. combined with serous 
chemosis. After the pus was evacuated by means of j n , 
in the temporal region, improvement soon folloi 

Abscesses of the periosteum of the roots of the im 
perforate the facial, more frequently than the lingual wa 
the jaw. The molars, however, form an exception to this rule. 
Destructive processes in the bone are less intensive and exten- 
sive than in the upper jaw. Still it is not uncommon for the 
entire facial wall, both of the alveoli and the jaw to be de- 
stroyed ; the lingual wall, also, of the lower jaw is frequently 
perforated, especially opposite the apices of the roots of the in- 
cisors. The margins of the bone, which bounds the parts where 
destruction has taken place, always terminate in thin i 
generally, have an oblique direction from below opwa 



* Dental Cosmos, 1867. 



ALVEOLAR ABSCESS. 221 

With abscesses of the periosteum of the roots of the under 
teeth, there is, always, great danger of the formation of fistulous 
tracks along the fasciae and, whether the fistulse open upon the 
cheek (salivary fistula), upon the margin of the lower jaw, in 
front of or behind the ear, in the cervical region, upon the nape 
of the neck or the thorax, their true character, frequently, is 
not recognized by physicians, and they are improperly treated. 

In proof of this fact, may be cited the following communica- 
tion, which was made to me by Prof. Strasky : " Several years 
ago, I was consulted by an elderly lady in regard to a set of 
artificial teeth. Presently, to my surprise, she began to arrange 
the dressing of a purulent ulcer, upon the left side of the chest, 
opposite the armpit, in the region of the fourth or fifth rib. To 
my question, as to what ailed her, she replied, that for three 
years, she had been under the care of the most noted physicians 
in the city, who had treated this ulcer with all sorts of salves 
and plasters, but to no purpose, for the ulcer which commenced 
as a small abscess, gradually increased in size, and became 
more painful. When I examined the mouth for the purpose of 
fitting the set of teeth, I found the left lower wisdom tooth 
deeply imbedded within the gums; the crown was quite de- 
stroyed by caries, the gums around it were detached, sensitive, 
and, upon pressure, pus oozed out from them. As I had pre- 
viously conjectured that the ulcer upon the thorax was de- 
pendent upon an affection of the tooth, I applied pressure from 
the angle of the jaw along the surface of the neck to the region 
of the ulcer, and became satisfied that pus escaped from two 
points of the ulcerated surface. The carious tooth was ex- 
tracted, and the ulcer healed in the course of a few weeks." 

Pagello* had under treatment a fistula which opened in the 
dimple of the chin and resisted every kind of treatment. The 
teeth, apparently, were sound. An infusion of madder was in- 
jected into the fistulous track, and, in a few days, the incisor, 
situated above the track, acquired a red color. The tooth was 
extracted, and the fistula speedily and entirely healed. 

Finally, it may be remarked, that inflammations of the peri- 

* L'abeille Medicale, 1856. 



222 INFLAMMATIONS. 

osteum of the root, resulting in abscesses and erosions of the 
jaw or tooth, occur also in animals. I have had the opportunity 
of observing instances of this kind in the horse and dog. In 
these cases, caries does not furnish the starting-point, a> 
usually, the case in man. 

Inflammatory affections of the periosteum of the jaw are of 
frequent occurrence, as a sequence of an inflammation of the 
pulp or root-membrane. 

The cases that, for the most part, come under the notice of 
dentists, are those of periostitis occurring upon the alv<- 
process as a sequence of caries of the teeth and whirl 
fined within narrow limits, though to be Bare, 'now and then, it 
is quite extensive. This inflammation i< manifested primarily 
by the appearance of a tumor upon the 1m.ho, which 
sioned by an oedematous swelling in the perimysium and sol 
taneous connective tissue, in consequence of a hindrance t<> the 
circulation. If purulent infiltration int.. the alreolus has taken 
place, the maxillary periosteum readily becomes similarly 
fected. Hence is developed a circumscribed j ich 

ends in suppuration and destroys the contiguous portions of the 
bone (Atlas, Figs. 124-127 inclusn 

Inflammations of the maxillary periosteum of thifl 
tion are of frequent occurrence and are rery much 
after the subsequent suppuration, especially by 
poorer classes, since, if the pus has a f,v" 
ness of the bone persists, to be sure, but tl, rach 

a severe character as to compel the patient to apply for relief. 
When the pus has a free exit, the face even is not perceptibly 
disfigured. The inflammation may assume an acute cb 
and give rise to an abundant purulent mass, which undermi 
the neighboring periosteum, cuts off the vascular supply 
corresponding segment of the jaw, and hence ne- 

crosis of the latter. 

When the suppurating periostitis, especially in n | or 

badly treated cases, has occasioned the death 'of tl. 
bone, the dead portion acts as a foreign body and in 
consecutive suppuration in its vicinity . :ula ia torm 

leading to the necrosed portion of the alveolar p* 



ALVEOLAR ABSCESS — PERIOSTITIS. 223 

detachment of the sequestrum is a slow process and, often, does 
not occur for months, recurrences of the inflammation being 
very frequent. A repair of the destroyed portion of the bone 
takes place in most cases. 

It is a familiar fact, that the alveolar process is fractured, 
not infrequently, by carelessness in the extraction of teeth, es- 
pecially of the lower molars. Unfavorable circumstances, for 
instance, deep position of the teeth, hooked roots, notable di- 
vergence or length of the same, marked fragility of the bone 
in persons of advanced age, render a fracture of the process 
possible, even with the utmost care in extraction. When a 
fracture occurs, it depends upon its extent and complexity, 
whether or not several teeth, together with their alveoli, will 
become necrosed. As a general rule, a slight splintered fracture 
readily heals, after the exfoliation of the fragments. Stumps 
of teeth and the attached root-membranes, which remain after 
ineffectual attempt- at extraction, not infrequently give rise to 
a localized periostitis, which is recovered from as soon as the 
necrosed stumps are extracted or expelled. 

Periosteal inflammations occurring during the period of den- 
tition are of especial importance, since, with children, inflam- 
matory affections generally run a more rapid course than with 
older people, particularly in an organ in which development 
takes place within small limits with comparative rapidity. The 
more extensive the infiltration of the maxillary periosteum, the 
greater is the danger that a larger portion of the jaw will be- 
come necrosed. Children of a scrofulous or tuberculous habit 
are the more liable to the occurrence of partial necrosis of the 
jaws, from the fact that in them the infiltration undergoes a 
speedy degeneration on account of the rapid proliferation of 



* Leynseele (Bullet. delaSoc. de Gand, 1855) describes a case of meningo- 
encephalitis which resulted from an ineffectual attempt to extract a tooth. 
The lower jaw was splintered at the part where the extraction was attempted. 
Pus worked its way along the bone, which became denuded, and ascended 
upon the inner surface of the ramus of the jaw to the base of the cranium ; 
it then entered the cranial cavity through the foramen ovale, spinosum and 
rotundum, where it spread out upon the base of the brain and became the 
origin of a meningo-encephalitis. 



224: INFLAMMATIONS. 

the elementary organs. C. 0. Weber- relates two cases which 
came under his observation (in children two and six years of 
age, respectively), where the periostitis acquired alarming pro- 
portions. 

Children, who are attacked with the eruptive diseases during 
the primary shedding of the teeth, especially when their sur- 
roundings are unfavorable or they are the subjects of the ah 
mentioned diatheses, are liable to be affected with a periostitis 
and necrosis of the jaw which Salter* has described as exanthcm- 
atous. Two cases of this kind came under his observation after 
variola, five after measles, fifteen or sixteen after scarlet f< 
and most of these cases occurred in children, five y 

Periostitis with necrosis, occurring as a sequence of 
eruption of the wisdom teeth, has already 
p. 202). 

Rheumatic periostitis, which generally is with cari- 

ous teeth, is due to exposure to cold and damp. If 
do not differ from those of common per: Traumatic peri- 

ostitis from fracture or contusion of the ja Be, from the 

effects of phosphorus or mercury, dyscrasic, which I 
scorbutus and cachexias, generally, do not usually cmm- an 
the treatment of the dentist, although, the freqaen 
of carious teeth and the consecutive inflammation of their 
periosteal membranes form an essential pn . or 

aggravating element, and require special treatment." 

The symptoms of periostitis of the u j n _ 

flammation of the periosteum of the root, vary according to its 
original seat. AlbrechtJ gives an excellent description of th 
m the following words: « When the periosteum of the root^ 
the front teeth is involved, the alveoli become distei. ;„- 

teralveolar depressions disappear, and the inrlamma: 
to the nasal cavity; the secretion of the mucous membrane of 
the latter is arrested, and its cartilaginous porti 
sitive. If the affection extends from the alveoli of the small 
"^^ th0 irrogulari: 

I fZ?T/ eT *^^^ Pithaund Billroth. 

J Su^eal diseases connected with the teeth in Holmes' System of Surgery, 

X Op. cit., p. 45. 



ALVEOLAR ABSCESS — PERIOSTITIS. 225 

on the facial surface disappear, the canine fossa is obliterated 
and bulges out if the intensity of the periostitis of the alveolar 
process increases sufficiently, and the periostitis extends, usually, 
even to the nasal process of the upper jaw, which becomes 
somewhat swollen and sensitive to pressure. If the inflamma- 
tion starts from the molars and bicuspids, instead of a depres- 
sion, a firm swelling becomes perceptible beneath the zygoma, 
produced by the swollen, upper jaw. If the two sides of the 
face are compared with each other, provided the periostitis is 
not bilateral, an extremely rare occurrence, the filling up of the 
zygomatic fossa becomes quite evident to the touch, even if it 
is inconsiderable. On the other hand, the swelling may attain 
such magnitude, that the surface of the jaw projects beyond 
that of the zygoma. The inflammation, sometimes, extends far 
beyond the affected tooth. The periosteum of the root may 
return to its normal condition, while the inflammatory process, 
or its sequelie, still persist in the periosteum of the jaw and 
give rise, in the latter locality, to important diseased processes. 
AVhen this occurs, it becomes a difficult matter to ascertain 
which tooth was the starting-point of the affection, as it is often 
requisite to remove this tooth in order to afford an escape for 
the pus which is pent up within the bone. 

"Periostitis, resulting from an extension of inflammation, 
occurs more frequently in the lower jaw than in the upper. 
After the alveolus of the tooth originally affected has become 
notably distended and painful, the ridge, which runs along 
above the basilar portion of the under jaw (basis manibuhe), 
disappears in the portions corresponding with the molars and 
becomes continuous with the basis. The latter then increases 
in thickness, becoming, in some cases, even five and six times 
as thick as it is in the normal condition ; the margin of the jaw 
now presents a thick shapeless bunch, which has the hardness 
of bone and spreads both to the outside and to the inside 
towards the cavity of the mouth. As long as the swelling is 
moderate in amount, it may be known that the process is still 
confined to the periosteum of the jaw ; but when it attains such 
large dimensions as mentioned above, either the inflammation 
has extended to the spongy portion of the bone, or purulent 

15 



226 INFLAMMATIOH 

infiltration has taken place into the bony tissue from the 
alveoli." 

If we make an anatomical study of jaws within which are 
carious teeth and abscesses of the ropt-perioeteom, and o 1 
the frequency and marked degree of purulent infi which 

takes place into the periosteum and bones, tl. 
that there is far from sufficient attention given to this aft- 
by physicians, and that, perhaps, many . which I 

nate fatally, originate from a consecutive suppurative 
or ostitis of the jaws. Fortunately. f purulent in- 

filtration result, finally, in perforation of the maxillary walk 
the pus obtains a free escape through the fistula which 
in the gums. 

The infiltration of pus takes place chiefly in tl. 
tion of the osseous tissue, and hence it la found, in the upper 
jaw, upon the lingual side of the incisors and 
of the bicuspids and molars, especiall .f the 

latter, and in the tuberosity. In the lower jaw, the liabil 
infiltration is greater, since the B 
the molars, extends to a considerable depth in 
the coronoid processes and condyles, 
layer of the bone is more compact, generally, ! 
by the pus takes place with greater diflic 

In the lower jaw, the enlargement of ti. 
of purulent infiltration, is most appi ■.} wall, in 

the vicinity of the external oblique line, tl. 
more or less effaced; in the upper jaw, on the facial i 
vicinity of the front teeth and towards the tul 
cancelli of the bones are distended in a] 
blood-red color or reddish-gray, or d 
of resorption, in consequence of the purulent infiltr. 
displayed in the form of sharp-edged holes, exc 
grooves, upon the surfaces of the alveolar j 
resorption starts from the Haversian canals U, as 

may easily be demonstrated by the gradual 
the development of the breaches in the osseous sul 

When a portion of the alveolar process 
puration or by necrosis, a cicatrization of the remaining 



ALVEOLAR ABSCESS — PERIOSTITIS. 'I'li 

ensues, similar to that which takes place after the extraction of 
teeth, except that the distortion is greater, varying with the 
amount of the previous loss of substance, that is, the cicatrix 
forms a deeper fossa-like depression upon the alveolar arch 
(Fig. 78). The adjacent surfaces of the alveoli of the contiguous 




teeth are frequently defective, in consequence of which the roots 
and their periosteal layers are exposed in the cicatrix. 

The pre-existence of a chronic periostitis may be clearly in- 
ferred, even in macerated jaws after the separation of the peri- 
osteum, if there is a deposit of a minutely-porous osteophyte 
(comp. New-formations). The very delicate and thin osteophyte 
formation, which may easily escape notice, is of frequent occur- 
rence and, generally, is limited to a quite small circuit in the 
vicinity of an alveolar abscess ; upon the lower jaw, however, it 
occurs, at intervals, over the greater portion of the facial wall, 
even along the coronoid and articular processes. Xow and then, 

* Fio. 78 shows a segment of the left lower maxillary arch, in which is 
the cicatrix of a circumscrihed necrosis of the alveolar process, corresponding 
to the first and second molars. The mental foramen, somewhat more pos- 
teriorly than usual, is situated underneath the apex of the root of the second 
bicuspid (a). The facial wall of the three front teeth is removed. The 
wisdom tooth (b) has a forward inclination, and most of the anterior wall of 
its alveolus is wanting. Between the latter tooth and the second bicuspid, 
a considerable loss of osseous substance is to be seen, in the form of a bowl- 
like fossa, with sharp outlines. In the persisting portion of the lingual wall 
of the jaw are several holes of various sizes. The fossa was lined with a thin, 
easily separable, connective-tissue membrane. Natural size. 



228 INFLAMMATIONS. 

in connection with caries of a single tooth, an osteophyte id met 
with which extends along the entire lower jaw upon both maxil- 
lary walls. 

Chronic periostitis, in the vicinity of the alveolar borders, 
frequently gives rise to proliferations of the compact os 
substance, which are described in connection with incn 
volume, as hypertrophy of the alveolar processes, 
or osteomata (comp. New-formations 

Nasal Cavity and Antrum. — When then- is insnffici* 
no escape for the pus of abscesses of the root-periosteum of the 
upper incisors or canines, and the al reads opwards, the 

bony floor of the nasal cavity becomes in vol \ I read J 

been observed; its periosteal covering and the corresponding 
portion of the mucous membrane become inflamed and j- 
tion, sometimes, ensues, by means of which t: 
the anterior nasal region. The skeleton, in so 
usually, an oval aperture, with sharp edges, the long diameter 
of which, transversely disposed, sometim 
centimetre, so that it communicates with the in 
the same side (Atlas, Fig. 12b*). In two specimens, I find that 
the abscess of the root-membrane, which penetrated the floor as 
above, originated from the lateral incisor. My colli 
contains a specimen, in which the perforation is in the middle 
segment of the floor, adjoining the ascen ral wall, 

nasal cavity, and the disease originated from a pel 
of the lingual root of the first molar. With exf 
affection of the molar roots, accompanied by chronic inflamma- 
tion of the root-membrane and periosteum of the jaw. the puru- 
lent infiltration also spreads within the 
the floor of the nasal cavities. Inflammatory affecti 
nasal mucous membrane, attended with catarrh or fistulous 
ulcers, appear then to be a more frequent sequence o( chronic 
inflammatory diseases of the teeth than was formerly sup] 

T\e sometimes meet with jaws, in which the Ungual 
particularly of the first molar, covered with a thin 
projects about three to four millimetres beyond the floor of* the 
antrum, or where the respective roots of the first two mo! 
that of the second bicuspid, covered with their periosteum, form 



NASAL CAVITY AND ANTRUM. 229 

free projections within the cavity. Less frequently, humped 
protuberances are found which are produced by the roots of the 
wisdom teeth or first bicuspids. When such a condition of 
things occurs, it is easy to understand, that, as a sequence of 
an inflammation of the root-membrane which ended in an abscess, 
the purulent accumulation has given rise to an inflammatory 
affection of the periosteal covering and, finally, of the mucous 
membrane of the antrum. Inflammatory, catarrhal swelling of 
the antrum, occurring either with or without periosteal inflam- 
mation of the contiguous teeth, occasions a sensation of dull 
pain ; the bone becomes sensitive, at times even under the 
slightest pressure ; the cheeks become somewhat swollen and 
©edematous, and, sometimes, the skin presents red spots. The 
affection is now termed empyema, and is accompanied by con- 
tinual pain with more or less intense exacerbations. T. Bell 
mentions the occurrence of caries (?) and exfoliation of the bones, 
in unfavorable cases, especially in scrofulous persons, and, ac- 
cording to his observations, if communication with the nasal 
cavity becomes closed, in consequence of the swelling of the 
mucous membrane, the symptoms become more serious from the 
accumulation of puriform mucus; the molars and bicuspids, on 
the same side, become loosened and tilted from their normal 
position, and the gums swollen and spongy. In cases, he says, 
where it cannot be expected that the teeth will become firm 
again, they should be extracted. Bell never saw a case of 
closure of the opening into the nasal cavity by granulations, 
but mentions an instructive case of a cyst filled with puriform 
mucus. One case of a purulent cyst of the antrum, in connec- 
tion with extensively carious roots of the bicuspids and molars, 
came under my observation. When the fluid, accumulated" 
within the antrum, had a more serous character, the affection 
used to be called hydrops. In these cases, the mucus also ac- 
quires a gelatinous appearance occasionally. 

As the cavity of the antrum increases in extent, the facial 
wall bulges considerably and becomes quite thin and trans- 
parent. The distension may also be perceptible in the direction 
of the palate or orbit and, sometimes, occasions a deviation of the 
eye from its normal position. As the former attains increased 



230 INFLAMMATIONS. 

proportions, the facial wall of the bone undergoes partial re- 
sorption, so that nothing is left but a membranous wall here 
and there, and the contained fluid may be determined by its 
fluctuation. 

The diagnosis is attended with difficulties, in some c 
the case may easily be confounded with an entirely difl 
tumor. Henry Smith* relates a case, where there was a puru- 
lent collection in the antrum, forming a notable tumor which it 
was decided to extirpate; but it began to improve, and the 
operation was abandoned. In doubtful . it is 

best, always, to make a puncture into the antrum through the 
alveolus of the second molar, after extracting the tooth, or 
through the canine fossa. The manner in which an explor 
puncture shall be made depends, however, upon : 
circumstances of the case. 

In favorable cases, the puriform mucufi _li the 

nasal cavity or downwards in the alveolar arch, if t 
root has fallen out or has been extracted. Sometin 
lous track persists, which, frequently. is as 
easily becomes occluded. The discharge may also occur in the 
direction of the orbit or the cheek, and 
and necrosis (comp. Salter's c 

Chronic irritation of the mucous membrance of the antrum, 
with or without a fistulous track leading from it. leadfl 
ening, recurrent, inflammatory swellings, papilliform, 
growths of connective tissue, or other kinds of new-formal 

Inflammation of this mucous membrane may ah 
by the penetration of foreign bodies into the antrum, 
picks, stumps of teeth which have been forced inl 
to extract them, fragments of bone from fractui 
wounds, &c. Prof. Strasky. of Lemb me a bri 

of a case of this kind. A boy nine years -Id came to him on 
account of pain in a left milk molar, and an ulcei 
on the same side. The father stated that a year 1 
boy fell into a water conduit, one and a half fathoms 
and framed with oaken posts and planks. After the hemorrhage 



British Journal of Dental Science, > 1 



NASAL CAVITY AND ANTRUM. 231 

from the cheek was checked, suppuration occurred in the cheek, 
and an ulcer was formed, which would not heal, in spite of very 
careful treatment. Strasky found a well-marked parulis, and 
extracted the painful, loose tooth which had pushed forward in 
its socket; a probe was then introduced through the socket 
from which pus mixed with blood escaped; it easily passed into 
the antrum, and by means of it a foreign body could be felt, 
which could, also, be reached by introducing the probe through 
the ulcer on the cheek. He succeeded, by means of a pointed 
pair of forceps, in extracting the foreign body which proved to 
be a conical piece of oak wood, fifteen millimetres in length 
and five millimetres thick. The part was carefully cleansed by 
syringing, and a sponge-tent was introduced, in order to avoid 
a premature closure, and kept in place until the healing of the 
bone and skin took place. In about three or four weeks, both 
the wounds, that upon the alveolus and the other upon the cheek, 
were cicatrized. 

F. Steiner* reported a case of dropsy of Flie antrum, which 
occurred in the private practice of Prof. Billroth. The affection 
appeared' as a sequence of a very irregular, extremely defective 
dentition, in a scrofulous girl, sixteen years of age. The only 
teeth that had made their appearance in the the upper jaw were 
three temporary and, subsequently, the three corresponding per- 
manent ones. The tumor had been forming for a year in the 
left upper jaw, and had attained the dimensions of an apple of 
medium size. The anterior wall of the cavit}' was partially 
removed, and, on examination at that part, no abnormally located 
tooth was found, but on excision of the posterior wall of the gum, 
the imbedded crown of a bicuspid was discovered. 



* Wiener mecl. Wochensehr., 1870. 



232 ATROPHIES, 



III. ATROPHIES. 

Atrophy of an organ arises from a partial or an entire per- 
manent withdrawal of its nutrition, ami is either p 
induced bj the gradual decline in the interchange of materials 
incident to advancing age, or secondary, 
as a sequence of inflammations, anomalies of tin- secretin! - 
pertrophies or new-formations in the organ itself -Me in 

the immediate vicinity, or in distant organs having a definite 
relation with the atrophic organ. 

It is scarcely possible to determine in eve; ther it 

is one of senile, or consecutive atrophy, and a careful ol 
of the clinical history of tin n alum- furnish I 

reasoning, especially when it is required t<> determine the pro- 
disposing causes of the consecutive atrophy. 

The senescence of the organs <»f mastication Deeds to ] 
nutely studied in order that the natural invol 
which occurs in old age. may not be confounded with a j 
logical process. The period at which the natural decay takes 
place is not fixed; one organ may be sul 
able conditions of nutrition that either the whole 
prematurely, while the other organs or the remaining 
of the same organ undergo comparatively no alteration within 
the same period. Premature decay ia induced by hereditary 
disposition, excessive irritation, and untimely abrasion. In all 
cases the diminished assimilative power of the elements 
gives rise, finally, to degenerated products within the | 
plasm and surrounding substance, which products ai • 
in the various organs except that they occur under did 
forms (Modalitaten). 

Dental Pulp.— Diminished vital activity in the pulp u 
played in manifold ways.* Fatty degem rat 
occurrence and is manifested, in a general way, by its dimin- 



* Vide deutsche Viertelj. f. Zahnbeilkunde o. Jahrg ,n der 

Zahnpulpe von M. Heider und C. Wedl. 



DENTAL PULP. 233 

ished volume and succulency, its recession and pale reddish-gray 
discoloration, with a trace of yellow. These indications, of 
course, are presented both by the coronal and radical pulp. 

Pulps of this description are covered by a cloudy layer, sepa- 
rable in the form of a membrane and composed of degenerated 
dentinal cells. The outlines of the latter are preserved, more 
or less, and they contain numerous luminous granules of various 
sizes, which produce the optical effect of fat-globules, but, also, 
lie loose between the cells and, evidently, are the occasion of the 
diminished transparency. The parenchyma of the pulp, also, 
shows a similar fatty degeneration, though to a less degree. 
In some parts, the fat-globules form chain-like or fusiform aggre- 
gations and follow the course of the vessels and nerves; in 
others, the minute fat-molecule> are scattered in the interstitial 
connective tissue which may be cleared up by the addition of 
acetic acid or carbonate of soda. In consequence of the abun- 
dance and ready accessibility of the nerves in the pulps and their 
roots, it is quite easy to demonstrate the granular, fatty meta- 
morphosis of the nerve-tubes which are uniformly thickened 
without any varicous enlargements (Atlas, Fig. 4T a ). It cannot 
be asserted, however, notwithstanding the existence of the latter 
evidences of necrobiosis, that the sensibility of such nerves is 
entirely destroyed, because the axis-cylinder may still be pre- 
served, though the nerve medulla has undergone a molecular 
degeneration, and still may be capable of performing its func- 
tions, though its conductibility be reduced to quite a low degree. 
On the other hand, it is impossible to assert absolutely that the 
medulla of each and every nerve-tube has undergone the fatty 
metamorphosis. 

The pulps of milk teeth, also, while the latter are undergoing 
resorption during the period of dedentition and, really, are se- 
nescent teeth, sometimes become the subjects of the above fatty 
degenerations which occur in the same manner and form as with 
the subsequent teeth. 

When calcifications occur, the coronal pulp, except in its pe- 
ripheral portions, is rendered less transparent by the deposition 
of roundish calcareous grains within its parenchyma which con- 
veys a gritty sensation when touched with a needle, and becomes 



234 ATROPHIES. 

more opaque in the mass as the calcification progresses. In the 
pulps of the roots, the appearances are still more striking; the 
calcareous particles, generally, are more completely arranged in 
them, so that, in some cases, they become as stiff as a wire. In 
order to examine calcifications with the eye alone, or with the 
aid of a lens, it is best to remove the pulp and all" dry, 

or to make longitudinal or cross-sections through the teeth con- 
taining calcified pulps. The chalky-white calcara 
are rendered much more distinct in the dried condition 
Figs. 51 and 53). 

The calcifications or cretefactions form, in I quite 

large coherent mass, as is the case, for example, npon the pleura 
or in atheromatous arteries; generally, hi 
sented in a reticular or nodular form. The 
than might be expected, even in tl. 
of the pulp is very extensive, since even these ad mi I 
tion in the direction of the organic envelopes which inclose the 
calcified portions. 

Upon minute examination the calcare in the 

coronal pulp appear in the form of nodules, of \ im- 

bedded in a mass of fine connective ti« the 

outer surfaces of which, especially if they hai 
siderable size, present a very delicate network 
and, sometimes, cup-shaped depres 
powers are employed (Atlas, Fig. 52). If the 
are removed by means of hydrochloric acid, tl 
ill-defined filamentous network, compoa 
trie layers, which bears a resemblance to coagulate 
cannot be regarded as such in a decalcified 
are no reasonable grounds for such a view. 
^ The small, nodular, calcareous concretions in the p 
m all probability, are produced in one of two ways : eitl 
calcification of cells, or in a manner am . ' ch 

they are produced in the urine of herbivorous anima :Iv 

from the semi-fluid, organic mass impregnated with 
salts, without the intervention of cells. As soon as a nucl 
of crystallization is established in the form of a firm transpan 
grain or an aggregation of minute granules, the growth pi 




DENTAL PULP. 235 

as may readily be demonstrated, by the deposition of new con- 
centric layers around the grain ; frequently, similar grains attach 
themselves to the periphery of the primary grain and give rise 
to the familiar mulberry forms ; contiguous grains, in some cases, 
coalesce and finally produce the larger nodular concretions 
which are visible to the nuked eve in the form of spheroids or 
spherical segments, arranged in clusters of a few or aggregated 
into a large mass. Now and then 
occur calcareous grains of a round, 
oval, or dumb-bell shape, around 
which are deposited very sharply 
defined, uniform, cortical la;. 
scarcely 0.001 of a millimetre 
apart from each other, which per- 
sist after the removal of the cal- i 
careous salts. (Fig. 79.) BH^^i % '■''■'.' 

The calcareous nodules present 
the following properties : a strong 

refractive power; the property of producing double refraction; 
if treated with dilute hydrochloric acid, decomposition ensues, 
with the liberation of bubbles of gas and a residue of an organic 
basis-structure; if treated with dilute sulphuric acid, numerous 
crystals of sulphate of lime are deposited. 

In the root-pulps, sometimes, also, in those of the crown, the 
concretions assume an oblong, cylindrical, spicated, or spindle 
form with two pointed extremities and their long diameters cor- 
responding with that of the radical pulp. They are located in the 
firm, interstitial bundles of connective tissue, the sheaths of the 
bloodvessels and nerves. In the tunica adventitial especially, of 

:f Fig. 70 shows a calcareous deposit in the central portion of a trans- 
versely divided pulp of the incisor of a horse. The deposit is seen in the 
centre and, like analogous ones which occurred in other places, presents a 
highly refractive power, agranular condition, a nucleus-like structure com- 
posed of minute spherical concretions, and a rounded outline. As these 
agglomerations were located near the central portion of the pulp, cavities of 
wide bloodvessels, transversely divided bundles of nerves (a, a), and capil- 
laries, interspersed here and there, occur in the section. Upon the periphery, 
connective-tissue fibres extending from the margin are to be seen, and 
roundish connective-tissue cells, also, are visible. Magnified 250 diameters. 



236 ATROPHIES. 

arteries, concretions of this description are frequently inter- 
spersed in elongated patches (Atlas. Fig. 48). The narrow 
cylindrical forms occasionally send out ramifications in the 
manner of fungus-threads, and these forms, probably, are pro- 
duced by obliterated thin bloodvessels which have ui 
calcification. The trunks of the nerve- not infrequently are 
so concealed within the calcareous shells that a careful disc 
tion is necessary in order to bring them into view, and the 
nerve-medulla of the tubes frequently degenerates into 
highly refractive mass which does not completely fill tl. 
of the tubes (Atlas, Fig. 47 1 ') ; the interstitial conn< 
of the trunks is reduced to membraniform, 
lamellae. The bloodvessels are obliterated and, except here and 
there where they are filled with necrotic blood, ai e »Hy 

empty and collapsed. Nothing is left of the dentin 
a scanty residue when the calcification is 

Cases occur less frequently where the walls of tl 
vessels, especially in the bodies of the pulps, undergo quite 
tensive calcification, so that the v. medium C a! 

gether with their branches or anast-.no. tie ] - 1 in 

calcareous envelopes (Atlas. Fig. 49), which gi 
a rigid appearance, a brittle character an 
Here and there, the inner coats of the vessels ar 
from out the calcareous cavity, which fad 
that the tunica adventUia of the v. 

latter calcareous incrustation. lly fiat: lite 

large, reticulated concretions are met with, tie 
tions of which may present evidene 

52). A combination of net-like calcareous plates with a i 
dentinal new-formation also occurs. 

The frequent occurrence of calcifications of the pulp is 
confined merely to old age and to the period ^ tl, 
of the roots of the milk teeth, but it occurs quite early i, 
teeth, independent of caries. The larger calcareous /rains n, 
not be confounded with the smaller dentinal new-form, 
latter, generally, consist of a compact, yellowish, trans] 
mass with a more or less nodulated surface and located beneath 
the superficial layer of the pulp or united with the dentine, and 



DENTAL PULP. 237 

containing dentinal canals, which, however, are rarefied. It is 
a fact of considerable interest, in a clinical point of view, that sen- 
sations of pain are not necessarily engendered, notwithstanding 
the very abundant calcareous deposits in the interstitial connec- 
tive tissue of the nerves. Under certain special conditions, how- 
ever, which we cannot explain and are difficult to determine, the 
calcareous agglomerations probably do excite a painful irritation. 

Colloid deposits are entirely absent in many cases of atrophic 
pulps, while in others they are present in abundance. They 
present the familiar globular formations which refract the light 
like opaque glass, and are unaffected by dilute acids; they lie 
among the fibres of connective tissue; frequently are attached 
to the tunica adventitia of the bloodvessels, or are adherent, 
within the cavities of the latter, to the inner coats and, also, are 
imbedded within the nerve-tubes. When the colloid masses are 
abundant and of small dimensions, with the exception of their 
L r la-sy aspect, they correspond somewhat with connective-tissue 
cells or their nuclei, at least with respect to their size, shape, 
and arrangement, and, probably, are the products of a colloid 
metamorphosis of these elements. The smooth, firm, trans- 
parent bodies which occur singly, in clusters, or are fused 
together into a glue-like mass, and fill, more or less, the cavity 
of the bloodvessel (Atlas, Fig. 50), are identical with the mi- 
nute, shining grains observed in the necrotic blood, which are 
colloid masses formed by a transformation of the globulin of the 
blood-corpuscles in the interior of the vessel. The different 
steps in this process of the transition of the red blood-corpuscles 
hito colloid masses may, indeed, be traced in suitable cases. 

The net-like atrophy or perversion of the pulp is a very in- 
teresting form, in a histological point of view. Pulps of this 
description are recognizable with the naked eye, by their flat- 
tened, shrivelled appearance and finely indented outer surfaces 
which, otherwise, are smooth. Their color is darker, gray-yel- 
low or reddish-brown, according as they contain a smaller or 
larger amount of necrotic blood which produces, also, indistinct, 
generally rust-brown spots. Further, they have a dry appear- 
ance, are brittle, and of about the consistence of parchment. 
The action of acetic acid, by means of which the connective-tis- 



238 ATROPHIES. 



sue # substances swell up and become clear, is reduced to a n 
mum. The pulp may become so diminished in thickness that it 
is as thin and translucent as tissue-paper. 

The diagnosis of net-like atrophy cannot, however, be made 
with the unaided eye in cases where it is not g 
in the above description, or is confined to narrow limits. A 
magnifying power of ten to twenty diameters ia Bufficiei 
quite a definite idea, where it is desired to observe, prii 
the network upon the outer surface and papilliform 
cesses which are located at uniform intervals iher 

upon the marginal portions (Atlas, Figs. 4<» and 4' dif- 

ferent colors produced by the blood, and the dilat. the 

vessels, may, also, be seen very well with the a 
power. 

If now one investigates more closely palps <-f this 
tion, beginning with the dentinal cells, the different \ 

the net-like degeneration must be taken in! 

the less advanced cases, tolerably well-preserved d< 

groups of them at least, are met with : 

they fade away and become unrecogni*abl< . 

left of them, in quite large tracts, bur a scanty 

ing of short filaments extending from a diaphai mi- 

form substance and penetrating the dentinal tub 

of the dentinal cells, consequently, have disa] 

If such a wasted group of dentinal cell* 

surface, it presents the appearance of a diaphanom 

perforated like a sieve, and is suggestive of a 

tinal tubules (Atlas, Figs. 42 and 44). 

The anatomy of the pulp, which has been considered in i - 

ceding section, is to be taken into account in connection with 

the development of net-like atrophy: ther , namelv. a 

withering of the reticulated connective-tissue cells and. 
he peripheral bloodvessels and nerves. The 

traced out in a series of case,. The network, which rem'. 

as a fi nal d and ma . nta . na thio e ^. miallv lhe 

ame character, is made up either of small meshes and d 
angle layer. Occasionally, very brilliant nuclei mav still 



DENTAL PULP. 239 

recognized at the points of junction of the trabecule; in more 
advanced cases, however, or elsewhere in the same pulp, they 
have disappeared. The resisting, rigid trabecule have a yel- 
lowish color, with transmitted light, a high refractive power, 
and give off processes which penetrate the delicate membrani- 
form, intermediate substance that fills up the meshes. The mar- 
ginal portions of the network upon the periphery of the pulp 
display to the best advantage the membraniform nature of the 
intermediate substance. 

The anomalies which are produced in the bloodvessels, in con- 
nection with net-like atrophy, arc very characteristic. In the 
pulp of teeth with single roots, the vessels of wider calibre not 
infrequently attain a transverse diameter of 0.2 of a millimetre, 
and even are larger; usually they are entirely empty, pursue 
an undulatory course (Atlas, Fig. 40) and their walls no longer 
present their proper arterial or venous character, those of the 
veins consisting merely of a delicate membrane containing barely 
discernible, shrivelled nuclei. In the smaller vessels, varicosities, 
lateral pouch-like dilatations, or bud-like offshoots are frequently 
met with (Atlas, Fig. 45). Very often, also, contractions of the 
larger vessels and strictures of the smaller ones are produced 
by the connective-tissue trabecule, which give rise to various, 
more or less, sinuous forms. In other places, coils of the ves- 
sels prevail. They contain only small clots of blood at inter- 
vals. It is worthy of remark, in reference to these orange-col- 
ored, rigid columns that form a homogeneous mass, that they 
present at one end a concavity in the form of a meniscus, a con- 
dition which may be explained by the adhesion of the glutinous 
blood to the wall of the vessel at the period of stasis (Atlas, Figs. 
43 and 44). Usually these are combined with products of meta- 
morphosed blood in the form of molecular precipitates, fatty- 
acid crystals, plates of cholesterin, kc. ; not infrequently the 
reticulated tissue has become tinged with blood from previous 
extravasations. Here and there the red corpuscles may still be 
recognized, deprived of their coloring matter, necrotic, and an- 
gular in consequence of their mutual pressure one against the 
other. 

The nerve-tubes present, very distinctly, the atrophic charac- 



240 ATROPHIES. 

ter which has been described above, and in transparent portions 
it may be traced without any previous preparation, by their no- 
tably flattened, as it were, mummified condition. 

Net-like atrophy occurs as an independent involution of the 
tissues, which, apparently, is unattended with pain, runs a cl 
course and affects, chiefly, the much worn teeth of old pe 
but, also, the milk teeth at the period of Bhedding the teeth and. 
more particularly, those which have but a single root. 

It arises from nutritive disturbances which are induced, pri- 
marily, by varicous expansions and spiral curvations of th< 
sels which are succeeded by stasis and effusion of the blood. The 
capillary system becomes entirely obliterated, and the < 
tissue, which serves as a stay or support for tl 
bloodvessels, likewise shrivels up. Nutrition and sensibility are 
completely arrested. The explanation of tie- m ore.fr* 
currence of general atrophy in the pulps than in oth 
may, perhaps, be found in their diminutive 
tively powerful pressure to which the worn 
subjected in mastication, and in the diminished el >f the 

dentine in old age. 

Sclerosis belongs to the rare affections of the pulps. T 
cord-like bundles of connective tissue interlace in the \ 
cious, resisting bodies of the pulps, forming Bharp ai 
each other, and between them minute fat-granul 
As the metamorphosis advances, the bundle - 
away. 

The different processes which have been d< ceur- 

ring in the retrograde metamorphosis of the dental pulp, 
times are combined, so that fatty degenerate s with cal- 

cification, colloid deposits with sclerosis, net-like atrophy with 
calcification and colloid deposits. Fatty degeneration an 
like metamorphosis very rarely are combined.* Atrophic pulps 
may even become the subject of an inflammatory a'' 
case the atrophy has not advanced too far. For insl 
and then a marked net-like atrophy is complicated with a puru- 
lent infiltration into the superficial portion of the pulp, 



* Hohl: Deutsche Yiertelj. f. ZuhnheilkunJe. 



DENTAL PULP. 241 

caries of the crown; partial gangrene, even, may ensue in an 
atrophic pulp. New-formations of dentine are frequently the 
forerunners of the atrophic process. 

Adhesions of the pulp to the internal surface of the dentine 
occur. The two structures become intimately united, so that, 
instead of admitting of ready and complete separation, as was 
the case originally, they become united by a delicate, transparent 
membrane which, even with the most extreme care, is easily 
torn and remains adherent, in patches, to the dentine. Such 
adhesions occur more often in the pulp-cavity than in the 
canal ; are limited usually to a quite small portion and are, 
most frequently, the concomitants of the net-like atrophy and 
chronic wasting of the pulp, in conjunction with caries. It may 
be observed in this connection, that when such agglutinations 
take place between the pulp and the dentine, the surface of the 
latter not infrequently has a rough appearance, being marked 
with numerous elevations and depressions. In a case of scle- 
- of the pulp of a canine, the apex of the pulp was attached 
to the internal surface of the dentine by means of a cord-like 
band which stretched between the dentine and apex of the root. 

The pigment deposits in atrophic pulps, varying according to 
their mode of origin, form dirty-yellow, reddish-yellow, brown- 
red, or dark-brown spots. Care must be taken, in particular 
3, not to regard the deposits of pigment as a direct element 
of the atrophic process, since they belong much more to an 
accessory pathological process. Thus, circumscribed or diffused 
extravasations of blood occur in conjunction witli different forms 
of atrophy and various transformations of color ensue, ac- 
companied by the precipitation of numerous crystals of hicma- 
toidin, just as in other organs, a subject which was considered 
in the section upon inflammatory affections of the pulp. 

The highest grade of atrophy is displayed in the degeneration 
of the pulp into a soft, greasy mass, unaccompanied by the odor 
of decomposition ; it is never a primary affection, but is the 
result of a previous inflammatory process. The mass is com- 
posed merely of a dirty brownish-yellow detritus, or traces of 
a fibrous structure, together with clusters of stellate fatty- 
acid crystals, may also be identified. A tooth, which has been 

1G 



2±2 ATROPHIES. 

the subject of a total decay of this description, is no I 
firmly attached within its alveolus. 

A notable diminution in the size of the pulp-cavity a, 
canal occurs in advanced age. The size diminishes in various 
ways, but is effected, always, by the continued deposition of new 
dentinal layers. The pulp-cavities of the lower molai 
ally, are reduced, not infrequently, to a trail SBure with 

narrow, short prolongations extending towards the masticating 
surface. In teeth with a single root, the pulp-cavity 
minished so much in length, as it is contracted lide to 

side. The internal dentinal surface is marked, frequently, with 
tiny, resisting, rounded excrescences. In old . the 

growth of the dentine is disproportionately within a 

limited area, and is abnormal in character, in other n 
formations of dentine occur.* The root-canal- more 

narrow, and the apertures at the extremities of the 
infrequently become indiscernible. 

Senile Dentine has, generally, a yellowish 
times, a sprinkling of brownish or dirty gray. Eu 
and brittleness may become so great that if such I • com- 

pressed sufficiently in a vice, they may easily be erack 
definite directions, and teeth witli a single root may be divided 
into two symmetrical portions. Another physical pecnliai 
presented in the increased translucency of certaii 
so-called horny character. 

As is well known, the latter is met with most frequently at 
the extremities of the roots, but may be continued, in old, much 
worn teeth, as far as the necks, indeed, in pla Q into the 

crowns. It is distinguished, also, by a yellowish hue which, 
upon the surface of cross-sections, is interrupted by the chalky- 
white tracings of the dentinal tubules filled with* air. an 
infrequently, presents an infundibuliform prolong 
the enamel layer. In the peripheral zone of such diaphi 
dentine, where the numerous, delicate ramifications of th< 
tinal canals occur, a faint tinge of gray becomes perceptible. 

By means of thin sections, it may readily be den, 



Vide the section upon Dentinal New-formations. 



SENILE DENTINE. 24:3 

that the increased translucency of the dentine is dependent 
upon the absence of air in the dentinal tubules, and that the 
more opaque portions, which usually correspond exactly with 
the course of the tubules and are white with reflected light, owe 
these peculiarities to the air contained in the tubules. 

The question at once arises : Do the dentinal tubules, or 
more strictly speaking, do the processes of the dentinal cells, 
generally, still persist in the diaphanous portions of the den- 
tine ? In order to determine this point, thin cross-sections 
were prepared from translucent portions of the extremities of 
roots, and by means of heated, dilute, hydrochloric acid, the 
processes in question were brought into view. In these experi- 
ments, no essential difference could be discovered between the 
translucent and less diaphanous portions of the dentine. 

In order to show whether processes of the dentinal cells of 
such horny roots still retain the property of imbibition, thin 
cross-sections of the latter in a dried condition were heated 
slightly and placed in a strong, ammoniacal, carmine solution, 
and afterwards treated with dilute acetic acid. The tinged sec- 
tions were then allowed to dry, or were treated with absolute 
alcohol, and placed in Canada balsam, when it was found that 
the coloring matter had penetrated even to the finest ramifica- 
tions of the processes of the dentinal cells. 

Since, then, it is" proved beyond a doubt, that the processes of 
the dentinal cells do exist in the translucent portions of senile 
dentine, and that they still retain the property of imbibition, it 
may be assumed, with a certain degree of plausibility, at least, 
that these processes, as well as other tissues, in the decay of 
advanced age have lost, more or less, their distensibility ; that 
their central vitreous substance has disappeared,* and that,- to- 
gether with the investing walls of the dentinal tubules, they 
have become closed in such a manner that the entrance of at- 
mospheric air is no longer possible. 

Still another point may be taken into consideration, as to 
whether or not a change is induced in the aggregation of the 
basis-substance, which may contribute to the production of the 

* Compare p. 44. 



244 ATROPHIES. 

translucency. Premising that the so-called dental cartilage 
gradually loses its succulency, then the inorganic particles, the 
calcareous salts, which are organically combined with the car- 
tilage, become more closely approximated, and their relative 
positions with respect to each other become altered. By this 
process, the general dimensions of the tooth will be 
and its physical properties will suffer a perceptible alteration. 
The subject of the resorption of senile dentine will be co 
ered farther on in connection with that of the cement. 

Cement. — The thickening of the 
is analogous to the continued formation of dentinal cells upon 
the internal surface of the dentine. A- I- well known, thick- 
ened cement is a very frequent occurrence: upon teeth with a 
single root, it is confined to the extremity and inc ipidlj 

towards the apex, while upon teeth with multiple 
tends not infrequently toAvards the neck of the tooth as far as 
the junction of the roots and forms, therefore, a uniform cov- 
ering over a considerable portion ; contemporaneous with this 
thickening process occurs a resorption of tin- dent 
and, in this respect, an analogy with 1 
also, resorption and the continued development of 
may be concurrent processes. For instance, upon the 
•of the flat bones of the skull, an expansion of the openii 
the Haversian canals and distinct excavations from I 
are met with, and, at the same time, a \ 

in the vicinity of the sutures. Ossification of the synchon- 
droses, along with the resorption of other portions of the bone, 
is a familiar occurrence in advanced aire. 

The new layers of cement are not alwa sited in a con- 

centric manner about the older ones, but frequently form 
or less acute and even right angles with the latter. -met- 

rical development of the bone-corpuscles does not obtain* e- 
where, since the striated, frequently turbid, intereorpuscular 
substance acquires such a preponderance in some localities that 
the bone-corpuscles become dispersed at wide intervals from 
each other. In other places, the bone-corpuscles are cl 
proximated, sometimes fused together, as it were. 'form 

a jagged, quite large cavity which is filled with calcan 



RESORPTION OF SENILE DENTINE AND CEMENT. 245 

The necrobiotic portions are of interest and may be traced for a 
considerable distance in layers of the thickened cement by the 
very turbid, dirty-yellow or yellowish-brown discolorations. 
Apparently, the intercorpuscular substance degenerates into 
granular, amorphous calcareous salts, amongst which the bone- 
corpuscles may still be recognized here and there. The cement 
of the teeth of old, larger mammals, is particularly instructive 
upon this point. 

The thickened senile cement is traversed, usually, by vascular 
canals which communicate with the vessels of the root-mem- 
brane, enter the cement, as a rule, in directions perpendicular 
to the surface of contact with the latter membrane, branch 
dichotomously and anastomose with each other by means of their 
branches. They are prolonged in their course as far as the 
dentine, indeed, under certain circumstances, even into the 
latter; their cavities are comparatively wide and, frequently, 
obliterated by amorphous, calcareous salts (comp. p. 53.) 

Resorption of Senile Dentine and Cement. — If we com- 
pare the periphery of the dentine of a series of teeth from old 
persons, even with the naked eye a zone will be perceived, cor- 
responding to the globular layer between the dentine and cement 
and appearing quite opaque with transmitted light and very 
white with reflected light. The interglobular spaces, replete 
with amorphous calcareous salts, have increased in extent and 
appear as cavities with irregularly indented outlines and fissure- 
like channels filled with calcareous salts. These cavities and 
channels not unfrequently penetrate into the substance of the 
dentine, where their dentiform prolongations are in direct con- 
nection with the dentinal tubules. Varicous, spindle-shaped dila- 
tations in the course of the dentinal tubules are met with, or 
opaque cavities with three, four or more dentations which are 
clustered in varying numbers between the dentinal tubules, and 
must not be confounded with bone-corpuscles. In very rare 
cases, the dentine is studded, quite generally or almost entirely, 
with uniformly distributed cavities filled with amorphous cal- 
careous salts, which give to it a mottled appearance. This con- 
dition may be explained by the occurrence of resorption of the 
dentinal substance along the dentinal tubules as a result of 



246 ATROPHIES. 

which these cavities are produced which become filled with 
amphorous calcareous salts. 

It has been mentioned above, that vascular canals occasionally 
penetrate from the cement into the peripheral portions of the 
dentine, where they may be traced for some distance, but they 
become obliterated directly by the deposition of calcareous 
grains and, occasionally, are surrounded by an osteoid substance. 

Excavations from resorption do not make their appearance 
upon the periphery of the dentine until the contiguous portions 
of the cement have undergone complete resorption. 

Cement which has undergone partial resorption frequently 
presents an appearance that is observed in connection with re- 
sorption of the roots of the milk teeth. While the familiar 
indentations produced by resorption are making their ai 
ance upon the periphery of the cement, sharply defil 
lated formations of osseous substance are observed in tin 
adjacent to the dentine, which not infrequently reach 
tance into the latter. (Atlas, Fig. 113.) 

The peripheral zone of the dentine, consequently, undt 
resorption in various ways, namely, by an increase in the 
ber and size of the interglobular Bpacea ; by an ext f the 

resorption process from the cement and by the encroachmi 
young osseous tissue. 

Examel.— The enamel of the teeth of elder! , uires 

the brittleness of glass, is cracked quite easily when - 
to pressure, and presents a smooth or splintered and. al 
conchoidal fractured surface. Senile enamel is disti 
by a yellowish or brownish-yellow color which is int. 
sometimes, with dark-brown spots. The latter are of limited 
areas and pass imperceptibly into the lighter layers: they are 
by no means to be considered as indicative of commencing 
caries, and may exist for years, as is verv well known, without 
any farther deterioration of the teeth. The dark discoloration 
may be present at intervals throughout the entire thick* 
the enamel, and yet the continuity of the latter may remain 
unimpaired ; this condition has its analogy in the oeeurren 
deposits of pigment in other organa during advanced 
molecular degeneration, however, also occurs in the enamel, 



SURFACES PRODUCED UPON CROWNS BY ATTRITION. 247 

which is displayed, even to the naked eye, in the form of white 
zones or spots ; it is associated with an interruption in the con- 
tinuity of the prisms and is morphologically identical with the 
imperfect formation ,of enamel. 

The enamel-membrane of senile teeth, as much of it as still 
persists, in comparison with that of younger, normal teeth, is 
thicker frequently, often contains deposits of dark-yellow, gray- 
brown or deep-brown, and from this to a black-brown pigment, 
or presents a molecular cloudiness, and is occupied by a mass of 
drops which have the shining appearance of fat and may be 
removed with ether. Sometimes this membrane presents tear- 
like, firm, colloid-like bodies with broad bases, the convex sur- 
faces of which project at the points where the membrane is 
reflected upon itself; they are distinguished by a faint lustre, a 
rounded exterior, and are irregularly disposed, being isolated in 
some parts and grouped together in others. (Atlas, Fig. 82.) 

Surfaces produced upon the Crowns by Attrition. — 
These are found upon the masticating surfaces and at the parts 
where adjacent crowns come into contact with each other. In 
the former case, they are produced by the trituration of food. 
Hence the nature of the latter, the manner in which it is pre- 
pared, its uniformity or variety, will have an important influence 
in the production of these surfaces. This, to be sure, is a diffi- 
cult matter to determine in the case of man, but with animals 
which receive special care and attention, with stud horses, for 
example, it is a matter of recognized importance. The more 
dry, and tougher the fodder, the longer and more forcible will 
be the process of mastication, and the sooner will corresponding 
abrasion of the teeth ensue.* 

* John K. Mummery (Trans, of the Odont. Soc. of G-reat Britain, new 
series, vol. ii) instituted very extended investigations to show that there is 
a notable difference with respect to the form in which, and the means by 
which, the teeth become worn away. Nations, like the Egyptians, and the 
Indians of the northwest coast of America, take but little pains in the 
preparation of their food which, consequently, often contains sand, so that, 
usually, their teeth are worn away evenly. If the food consists of hard seeds, 
roots, or tough meat, then the surfaces of the first molars are found to be 
most worn away, upon the lingual side in the upper jaw and upon the labial 
side in the lower jaw. With those who subsist upon an abundance of highly 



248 ATROPHIES. 

.Generally speaking, the surfaces become worn away upon the 
tubercles and edges at the points of contact between the upper 
and lower teeth, where they glide upon each other in certain 
directions during the act of chewing. Projecting crow;, 
worn down very soon ; if their axes are nearly perpendicular, 
they are worn away in a more or less horizontal direction ; 
those obliquely situated are worn in an oblique direction, and 
those having no crowns opposite them are not subjected to fric- 
tion. Since the crowns, and particularly the inch 
tubercles of the teeth of the upper and lower jan . lively, 

are inclined towards one another, and the act of chewing :- 
formed in definite curves, the facets, produced by attrition, arc- 
observed, also, to assume an oblique disposition, those of the 
teeth being located upon the facial Bide, and those of the upper 
teeth upon the lingual side. The approximation of the j 
of the facets to the horizontal direction depends nt 
of inclination of the opposing coronal :r 

When the entire thickness of the enamel lias been irorn I 
the summit of the dentine, at the corresponding point, 
similarly involved, so that the surface of attrition pi 
island of dentine surrounded by enamel. If the cron 
down nearly to the neck of the tooth, a greater portion of the 
dentine becomes exposed and presents a polished Burface like 
that of a mirror, not infrequently becomes excavated as the 
process progresses, has a yellowish or brownish-yell 
and, at last, forms merely a thin covering over the dental pulp. 
The enamel persists only upon the remaining lateral portions. 
If the abrasion of the thin dentinal covering inoed, the 

atrophic dental pulp, which generally has been rendered firm by 
a dentinal new-formation or has undergone partial cal 
becomes exposed and is perceptible in the centre of the : 
eating surface as a defined body surrounded by dentine, 
shrinking of the alveolar process has already commenced, then 



- - 



nitrogenous food, the pulps of the tooth gradually become - 

ondary dentine and the tooth frequently is worn au 

without the occurrence of an alveolar abscess ; on the contrary, in - - 

there is a defective nourishment, inflammations, abscesses, ami extern 

■sorption of the alveoli are constantly observed 



SURFACES PRODUCED UPON CROWNS BY ATTRITION. 249 

the entire neck of the tooth will become worn away, and even 
the contiguous projecting portions of the roots may be involved 
in the process. 

As the crowns become more and more worn away, the ser- 
pentine curve, which is described by all the coronal margins in 
common, gradually disappears, and finally the dental arches of 
the upper and lower jaws come into contact by means of broad 
surfaces, and the lower half of the face is shortened. 

From the degree to which the teeth are worn away, a probable 
conclusion may be drawn in regard to the age of an individual. 
After considerable practice, it is possible to determine the age 
within at least five years, from the latter and accessory data, 
as, for instance, from the variations in the color of the teeth 
and from the changes presented by the alveolar borders, &c. 
In drawing conclusions of this kind, however, individual peculi- 
arities must also be taken into account. The time required for 
a certain amount of wear depends upon the hardness or density 
which varies in different teeth. This may be determined, most 
satisfactorily, in regard to milk teeth which, in consequence of 
their slight density, present evidences of attrition in a compara- 
tively short period. Frequently, also, sets of teeth are found 
in young persons which are comparatively stronger than usual, 
and such teeth are but little worn when the individuals become 
advanced in age. 

With animals that are fed upon a uniform kind of food, the 
teeth become worn away in a quite constant manner. The two 
Guchters, father and son, of Hanover,* investigated this point 
and ascertained that the amount lost by attrition upon the per- 
manent incisors of the anterior and posterior jaws observed a 
tolerably constant measurement, namely, a line annually. The 
shape of the surfaces produced by attrition of the incisors cor- 
responds with transverse sections of the latter, and are roundish, 
triangular, oblong, &c. Hence, from these data it is possible to 
determine the age of a horse with tolerable accuracy beyond the 
period of dentition, even to the thirtieth year. As the horse 
grows old, and the uniform abrasion of the incisors is continued, 

* Beurtheilungslehre des Pferdes. 



250 ATROPHIES. 

the'arches formed by the respective sets of teeth disappear, and 
the teeth gradually acquire a position in a straight line. 

In entirely normal sets of human teeth, facets from attriti 
first make their appearance upon the incisors, the promin 
blunt points upon the incisive edges of which disappear; tl 
then become perceptible upon the outer portions of the cron 
of the first and second molars of the lower jaw. and later Q] 
the internal coronal borders of the corresponding teeth of the 
upper jaw. The explanation of these familiar appearances is to 
be found in the position of the teeth, in accordance with which 
the facial coronal borders of the lower molars impinge upon the 
lingual borders of the upper molars, and the two 1 iub- 

jected to friction, in the vibratory movements of mastica! 
In this way, facets are produced opposite each other upon the 
prominent points of the above-mentioned coronal 
at first, are barely a millimetre Bquare, but as the ] 
tinues, they increase in size, and the prominence of the 
gradually becomes lost; still later, quite largo inclined fa 
are produced which involve the entire outer and inner 
the crowns respectively. The previously sharp 
molars frequently are rounded, with scarcely any ap- 

pearance. The wisdom teeth, on account of their laf hen 

incomplete advance to the level of the masticating Burf 
come worn away at a later period and to a gree than the 

other teeth. 

The facial, coronal tubercles of the bicuspids of the lower jaw- 
are worn away obliquely outwards; the lingual tubercles, small 
and situated at a much lower level, are not involved until the 
former are almost entirely worn away and the dentine. • 
become exposed in the form of a yellow band. Upon I 
tubercles of the upper bicuspids, facets are produced which 
inclined in opposite directions. That upon the facial tub* 
appears first, and is larger than the other. 

The lower canines present two obliquely-situated facets upon 
their facial surfaces, one of which is directed anteriorly, and 
the other posteriorly. As the process continues, the two small 
facets disappear and give place to a larger one directed towards 
the face, in the centre of which the polished dentine 



SURFACES PRODUCED UPON CROWNS BY ATTRITION. 251 

perceptible as a transverse band. The upper canines, likewise, 
present two facets which meet at an angle ; these, however, are 
located upon the lingual side of the coronal apex ; in the more 
advanced stages, a larger facet, inclined towards the tongue, is 
met with. 

Upon the lower incisors, the facets are obliquely situated, 
being directed from the coronal edge towards the face, while 
those upon the upper teeth are directed towards the tongue. 
In advanced stages of the process, the dentine is exposed and 
presents the appearance of a transverse yellow band ; a quite 
opaque, firm portion is frequently observed in the centre of the 
latter, which Hunter, long ago, and Prochaska, described as a 
commencing hard new-formation which is to serve for the closure 
of the pulp-cavity (comp. Dentinal New-formations). 

As the character of the attrition depends upon the position 
of the two opposing teeth in the upper and lower jaw respec- 
tively, and anomalies of position occur very frequently and in 
infinite variety, it follows that the surfaces which are produced 
by attrition present an endless variety. With very prominent 
jaws, these facets assume an oblique direction which approxi- 
mates the perpendicular. With an upright set of teeth, in which 
the axes of the dental crowns have a nearly perpendicular direc- 
tion from above downward, the facets necessarily assume a 
horizontal direction. 

With asymmetrical jaws, where the masticating surfaces of 
the two sets do not correspond with each other, chewing is con- 
fined to one side, and the teeth of that side become much worn, 
and in a very oblique direction. The teeth, as a whole, then 
acquire a distorted arrangement, and give rise to a corresponding 
distortion of the mouth. 

When all the teeth of one or another kind are wanting, for 
example, all the upper molars on the right side, mastication is 
performed only upon the left side posteriorly, and the molars 
upon the latter side become worn down obliquely and much 
earlier. If the upper molars of both jaws are wanting, masti- 
cation is transferred to the front teeth which acquire large, 
more or less obliquely or horizontally-disposed facets. 

When a tooth is lost, the opposite one, deprived of its antago- 



252 ATROPHIES. 

niSt in biting, ceases to exercise its function and experiences no 
more wear from attrition. The tooth which loses the support of 
its neighbor upon one side, as will be noticed later in connection^ 
with the subject of cicatrization of the dental sockets, becomes 
inclined towards its newly-acquired neighbor, and, as a result of 
this, the correspondence between the crown of the dislocated 
tooth with that of its non-dislocated opposite is 1. If. 

for example, a second lower molar acquires an inclination from 
behind forwards, subsequent to the loss of the first molar, then 
the facet from attrition upon the former will be directed obliqi* 
backwards, and that upon the second upper molar obliqu 
forwards. We may, also, determine tb 
from the direction and size of the facet upon a tooth. 

The dental crowns, also, are subjected to attrition at tl 
where they come into contact with the crowns of adj eth, 

a familiar met to every dentist. The frwti 
crowns, produced in this way. are described by A. Zsigmondi* 
as "interstitial." They are produced by the m the 

teeth in their sockets during mastication and. th< 
occur only when adjacent teeth come into contact with each 
other. Of course, the wisdom teeth present none upon their 
posterior coronal surfaces. The nature of the contact 
with different teeth and, therefore, we find a variety in the 
presented by the frictional surfaces; indeed the i 
sarily change, if the position of a tooth in its relation to thai 
its neighbor is altered in any way. With reference to the latter 
point, Zsigmondi makes the following - 

^'The frictional surfaces resulting from the the 

incisors with each other, and with' the canines ling 

with the thin lateral margins of the former), are narrow. long - 
tudinally disposed, and more or less oval in shape ; where the 
rounded posterior surfaces of the canines come in ith 

the first bicuspids, they are roundish: tl _ rota 

friction between the first and second bicus] a 
larger, transversely disposed, and more or less oval 01 g nil 

m shape; finally, those from friction between th s 



Vierteljahrschr. f. Zahnh., 



SURFACES PRODUCED UPON CROWNS BY ATTRITION. 253 

pids and first molars and, also, from contact of the molars with 
each other (corresponding to the broad surfaces of contact of 
the latter), are considerably larger and broader, and, like the 
preceding ones, are disposed from side to side and of an oval or 
polygonal shape." 

Wedge-shaped defects upon the facial surfaces of the necks of 
teeth. — Sometimes, though rarely, a curious breach of substance 
(Usur) is observed upon the facial aspect of the neck, particu- 
larly of the incisors and molars. These defects are bounded by 
sharp edges, as if artificially made with a file (Atlas, Fig. 99), 
and present two surfaces, one horizontal and the other inclined 
at an angle of 45°. The wedge-shaped depressions are one to 
two millimetres in depth, their edges are very sharp, their sur- 
faces have a polished appearance. Persons, upon whose teeth 
they occur, know nothing respecting their origin, nor have den- 
tists, as it appears, made any extended investigations with ref- 
erence to tli is point. Fox* speaks of a removal of the enamel 
which is not produced by caries. This affection, he says, occurs 
upon the labial surfaces of the incisors particularly, which ap- 
pear as if they had been gnawed. After the enamel is destroyed, 
a portion of the dentine becomes involved, and the rest acquires 
a brownish color, is highly polished in appearance, and will often 
remain in this condition for a number of years. In other cases, 
he observed teeth which presented an appearance as if a small 
round file had been applied to their labial surfaces, in close 
proximity to the gums. In these cases, the molars participate 
in the disease. lie states that, posssibly the saliva may have 
some influence, and that the friction of the lips, also, may con- 
tribute to the removal of the enamel. 

The view, that these cases are instances of healed caries of 
the gum, cannot be entertained, as the defect is too sharply de- 
fined; nor is it possible to detect anj traces of previous caries of 
the gum. The fact, that such defects, so far as our present knowl- 
edge extends, are never found upon the lingual surfaces of the 
neck, indicates that their cause is to be sought for upon the 
facial side. Sometimes, the mucous membrane of the cheeks 

* Op. cit., p. 49. 



254 ATROPHIES. 

and lips is raised into a fold opposite the dental arches. In 
many cases, a tendinous expansion is observed upon the facial 
surface of the gums of the lower jaw, which gradually becomes 
narrower and terminates with a ridge of connective tissue which 
is attached to the neck of a bicuspid or molar tooth. It may 
be well to consider in future cases, whether any relation c.\ 
between the defects upon the neck of the tooth and th 
or ridges.* 

Gums. — The clinical appearances j 
of the gums comprise, chiefly, loss of their r ami uni: 

turgescence. The color is changed 
yellowish and, sometimes, blue-reddish when th< 
ter is in excess, in which latter cases circumscribed swellings occur 
here and there. The dimensions of the gums are diminisl 
since the margins recede from the uecks of the teeth. 
frequently, superficial erosions occur which art I with a 

thin discolored layer. Generally, the gingival mi the 

lower incisors are the first to be affected with by; 

those of the upper incisors are less frequently ii, 'nan 

the preceding, and those of the lower molars ami bicuspi 
are more often affected than those of the - 
teeth. 

In senile atrophy there ensues an attenuation of the papillary 
portion, corium, and submucous connective with 

a wasting of the contiguous periosteum of the alveolar pr 
The epithelial layers become quite dry and hard, and ei 
leaving the jaws covered with a layer of cells un 
degeneration. The attachment of the gums to the : be 

teeth is loosened. The papillae of the gums are flat, beir 

parenchyma is clouded by a molecular fat-granular mass, the 
capillaries are obliterated. The nerve-trunks of the submu- 
cous connective tissue acquire a molecular cloudiness beir 
more delicate branches are no longer recognisable . 
quence of the cloudiness of the contents of the nerv. nd 
of the connective-tissue investments. The com, 
cells and their nuclei present, in places, a shrivelled appear*, 
I he connective tissue is sclerosed. 



Comp. the remarks, p. 17-3. 



GUMS — ROOT-MEMBRANE — ALVEOLUS. 255 

Various causes may give rise to a premature atrophy, among 
which may be enumerated abrasion of the contiguous dental 
crowns in an oblique direction, neglect of cleanliness, accumu- 
lation of tartar upon the necks of the teeth and the adjacent 
coronal portions. 

Atony of the Grams. — From the fact that the first indications 
of that affection of the blood called scorbutus are presented by 
the gums, which acquire a deep red color, become sppngy and 
bleed spontaneously, it has been customary to apply the term 
scorbutic to all those affections of the gums which present one 
or more of the above appearances, although they may have noth- 
ing in common with scorbutus, except, perhaps, a few symp- 
toms. The condition of sponginess and laxity of the tissue, and 
even those changes, also, which are induced by tartar, are de- 
scribed as an atonic condition. 

Lax gums present a dark-red color, a swollen, spongy, and 
inelastic texture; the margins, which should form a firm invest- 
ment around the necks of the teeth, are swollen and uneven, 
recede from the necks, or, as is the case frequently, cover over 
half the crown. The points of junction of the gingival arches 
upon two adjacent teeth are transformed into shapeless masses. 
Under even very slight contact, an effusion of dark-red blood 
ensues. In some cases, this condition involves the entire gums, 
in others, it is limited to a portion of them. As it is impossi- 
ble, with such a condition, to keep the teeth clean, tartar ac- 
cumulates beneath the lax and swollen gums and, in this case, is 
the result and not the cause of the affection. Passive conges- 
tions, induced by the atony of the organic muscular fibres of 
the bloodvessels, give rise to hemorrhages which, in rare cases, 
are so severe as to be checked with difficulty. 

Root-Membrane and Alveolus. — In old age, the root-mem- 
brane becomes thicker, more compact, less succulent, firmer, 
more cloudy, and is more adherent to the root and to the interior 
of the socket by means of fibrous tissue which is insinuated be- 
tween it and the above surfaces; hence it acquires a felted ap- 
pearance and, sometimes, the lustre of tendon. The histological 
changes in it are analogous to those presented by the atrophic 
gum. 



256 ATROPHIES. 



Calcifications are not infrequent occurrences in the root-mem- 
brane of old age. Sometimes, they are found in the form of 
small granular concretions; at others, they present larger globu- 
lar bodies which have a strong refractive power; in some in- 
stances, they are without any recognizable structure, in otl 
they present a radiated or concentric lamination: they produce 
the phenomena of double refraction, and when treated with di- 
lute hydrochloric acid, a decomposition ensues with the liberation 
of bubbles of gas, and a deposit of an organic 
(Atlas, Fig. 121.) 

It is a notable fact that ossification of the root-membran< 
never been observed, at least in man, notwithstanding the I 
quent occurrence of calcifications. 

The effects of its atrophy may be traced partly in the cei 
of the tooth and partly in the socket. The cement, which, usually, 
has become thicker with advancing age, and< 
{vide supra), and the socket likewise is similarly affected. '! 
extent of the resorption upon the socket bears a direct relaf 
to the deposit of osseous layers upon the cement, and 
apparent at the closed extremity of the former from the I 
that the cement layers are more numerously disposed near the 
apex of the root. The wasting of the the 

free margin, is still more apparent in the vicinity of the hit 
especially upon the facial side, and .is distinguished by 
creased porosity. The foramina in the alveolar wall, for the 
transmission of bloodvessels and nerves, r, their 

osseous margins are sharpened to a thin 
produced by resorption, such as have been r- 
may be found in suitable thin sections, and d i s 
tissue substances are met with, associated with the obi ite rati 
of the bloodvessels and nerves. Sometimes, adj 
by the resorption of their borders, are united i 
quite large aperture with a festooned margin. 

As the resorption of the osseous substance of the a 
vances round about the alveolar border, the walls o( 
the facial especially, become shorter, the gums -lie 

same time, and the neck and contiguous portions ^ th 
sometimes, even as far as the spices, are exposed. In 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 257 

quence of this process, the attachment of the teeth becomes 
loosened, and all the more so when there is a contemporaneous 
resorption of the cement. 

Wasting of the sockets generally occurs, primarily, upon those 
teeth whose gums present evidences of atrophy. 

Maxillary Periosteum and Maxillary Bones. — Atrophy 
of the former presents the same morphological changes as the 
periosteum of the root. 

Senile wanting of the bone is accompanied, in many cases, by 
a marked fatty metamorphosis of the soft parts contained in the 
medullary spaces and canals, whereby a yellowish fat pervades 
the osseous substance, which imparts a greasy sensation to the 
touch. As fatty degeneration of the medullary matter becomes 
extensive, the osseous lamellae, which have become attenuated, 
are hidden from view by the general fatty appearance imparted 
by the former. The medullary spaces become expanded and 
the cortical substance is reduced, finally, to a thin plate. If the 
senile wasting is unaccompanied by fatty degeneration, these 
appearances are all the more evident. 

The upper jaw, with its thin cortical substance, displays the 
senile rarefaction of the bone much more distinctly than the 
lower jaw, with its thicker cortex and more compact structure 
generally. The palatine process of the upper jaw, the facial 
wall of the antrum and, also, the horizontal portions of the 
palate bones, become as thin as the lamina papyracea of the 
ethmoid bone. The branching Haversian canals upon the super- 
ficial portions of these bones present the appearance of very 
delicate vascular ramifications, which appear luminous with re- 
flected light and opaque with transmitted light. If very thin 
transparent sections, which may readily be made with the scis- 
sors, are examined, localities will be found which do not contain 
any, or only a few bone-corpuscles, and present, principally, ex- 
cavations produced by resorption. In such places, a peripheral 
has succeeded the above-mentioned central resorption in the 
cancelli of the bone. The extreme degree of brittleness of the 
bone incident to old age approaches the condition which Lob- 

17 



258 ATROPHIES. 

stein* described as osteopsathyrosis (fragilitis vitrea), and Rok- 
itanskyt as excentric atrophy. 

The marked brittleness of senile jaws is to be borne in mind 
by the practical dentist, when he is called upon to extract teeth 
still firmly implanted, on account of caries, or to adapt an arti- 
ficial set, since, even with all possible care in the operation of 
extraction, particularly with the posterior molars of the upper 
jaw, a fracture of the contiguous portion of the jaw a rery 
easily produced, which is all the more troublesome, from the 
fact that the parts unite very slowly. 

The processes which ensue in the alveoli, whether the teeth 
fall out spontaneously or are extracted artificially, tl 
ally the same, and their description is introduced 
without a thorough knowledge of the process of 
the changes which ensue in atrophy of the jaws cannot I 
predated, and, moreover, the process is accompani 
of the socket. Heider and Wedl published I 
gations with reference to this Bubjecl 

When a tooth is extracted, the blot - and nerves of the 

periosteum of the root with the connective ties Dying 

them, and the afferent and efferent n the pulp, together 

with the nerves in relation with them, are torn away, and the 
socket, deprived of the tooth, is filled with coagulated blood 
which serves as a natural plug in checking further hemon 
If the socket and gums receive no more injury than i.> in< 
to the mere separation of the tooth, then the gums maintain 
their normal color and, after a few days, their free mi 
found to be approximated towards each other : between them, 
a pale grayish substance, decolorized fibrin of the bin 
frequently observed, which, sometimes, deceives the pa 
that they not infrequently return to the dentist with th< 
that they have discovered suppuration in the wound. Ii. 
where the gums are not lacerated or bruised and the Bocket is 
not fractured, the cicatrization always ensues without anv sup- 
puration; indeed, the whole process is unattended with pain, and 

* Path. Anat. libers, von Neurohr., Bd. ii, p. 

f Manual of Path. Anat.. trans, by C. H. Moore, vol. iii. P . I 
X Viertelj. f. Zahnheilk., 1866. 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 259 

in a few weeks the patients are able to chew upon the side from 
which the tooth was extracted. But when teeth are removed 
during the existence of an inflammation of the root-membrane, 
painful sensations persist for several days within the socket, 
and, in very rare cases, an acute very intense pain, without any 
definite inflammatory symptoms, succeeds the extraction of a 
tooth. 

The root-membrane, especially with teeth extracted from 
jaws of young persons, remains attached in the form of a 
closely adherent investment, extending from the neck to the 
apex of the roots, and the vascular ramifications, injected with 
the blood, may be distinctly traced. In most cases, however, 
the contiguous portion of the membrane is torn, so that a part 
of it remains adherent to the alveolus, while the remainder is 
attached to the extracted tooth. That portion, on the other 
hand, which is in immediate relation with the submucous layer 
of the gums and is distinguished b; its more compact structure 
and its numerous nerves and vascular plexuses, is always sepa- 
rated from its attachment to the neck of the tooth. Since then, 
in most cases, the root-membrane is partially, sometimes, even 
entirely, separated by the extraction of a tooth, and frequently, 
indeed, is destroyed by a previous morbid process, without 
effecting any variation in the phenomena of the cicatrization, it 
cannot be claimed that the root-membrane has any share in the 
latter process. The alveolus undergoes entire resorption, since 
no trace of it can be discovered in the completed cicatrix. 

If an entire series of macerated alveolar cicatrices are ex- 
amined in the first stages of the process, by means of horizontal 
and longitudinal sections, it will be seen that, first of all, osse- 
ous trabecular with free, pointed, or clavate extremities, are de- 
veloped into the cavity previously occupied by the root, where 
they unite with others. Similar trabeculse penetrate from the 
alveolar border and join with those which extend from the former 
wall of the socket; these together form a spongy, slender, 
framework of osseous substance which fills up the cavity, near 
the superficial portion of which a fossa-like depression is still 
perceptible, and this disappears more and more, as the cicatri- 
zation progresses (Atlas, Fig. 132) ; the delicate, porous, osseous 



2G0 



ATROPHIES. 



lajer of the socket and its free margin, likewise, gradually 

appear. Vascularized, connective-tissue granulation, form the 
centre of ossification of the cicatrix ; these grow out from the 
gaps of the alveolus, and become ossified ; they also appear to 
give rise to the resorption of the hitter. 

The laceration of the gum, produced by -ation fi 

the neck of the tooth, is healed contempt Bly with I 

granulation in the socket. At the commencement of the ci 
trization of the membrane, very soft, deep-red papilla 
nective tissue, which bleed easily (granulatiou — 1 
chen), are observed growing out from tl 
and these soon cover the socket. The papill 
coalesce, and then there is presented a 
cularized cicatrix of the mucons membran 
upon its outer surface and covered with epithelia 

The second stage, that of consolidation, ' the 

first. The swelling, redness, and Bnccnlency diminish, the 
pallid, cicatricial tissue becom< 3 

a considerable period, a shallow groove, with slightly swollen 
margins in close proximity to each other, » '!>- 

rection of the alveolar border and. eventually. irly 

the consistence of tendon. Perpendicular " ; > a 

dense cicatrix of the gum display a gradual disappear 
the papillary portion, in the vicinity of the cicatrix 
117), leaving only a flattened corium which 
slight elevations and depressions and ed with a thick 

layer of laminated epithelium. The bio, 
which, in the gum, were uniformly disposed, Bince bran 
tended perpendicularly towards the papillae from the 
tally disposed vessels and nerves, assume in tin 
a more oblique arrangement and irregular distribution. 
bloodvessels are obliterated as the eoi. n and thicket 

of the cicatrix increases, and the latter underg 
ing contraction. Finally, a tense, sharp ridge is for: 
infrequently, along the cicatrized alveoli. 

Coincident with the consolidation of the cicatrix 
mucous membrane occurs that of the bony call; 
of the maxillary periosteum which invests the outer surface of 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 261 

the cicatrix, becomes very dense, and consists of tendon-like, 
tough bundles of fibres which are intimately united with the 
superficial bony substance. The osseous lamellae within the 
socket are more closely compacted, especially near the masti- 
cating surface, this condition being more distinctly marked in 
the under than in the upper jaw. 

When only one tooth is removed, the teeth adjacent to the 
socket become approximated so closely, that the cicatrix disap- 
pears, apparently, more properly speaking, becomes partially 
concealed. Hunter called special attention to this process and 
illustrated, in a very instructive manner, the changes of posi- 
tion. On examination, namely, it will be found tha.t a crescent- 
shaped depression remains upon the cicatrized alveolar border, 
extending, upon either side, to the borders of the adjacent teeth 
which are still retained. In the upper jaw, this depression is 
directed downwards, and upwards in the lower jaw, its greatest 
depth, corresponding with the longitudinal axis of the pre-ex- 
isting alveolus, measures about one-fourth that of the axis 
mentioned. 

When the cicatrization involves two or more contiguous 
sockets, the perpendicular septa between them undergo a partial 
resorption, and from both the facial and lingual walls a bevelled, 
sharp-edged callus is developed, composed of a compact cortical 
substance (Fig. 80). Sometimes the cicatrix is more flattened 
and the projecting lamellae upon its surface lock into one another, 
presenting, not infrequently, an appearance similar to that of a 
bony suture. Small, irregular, pitted depressions filled with 
sclerotic connective tissue are often met with upon the site of 
the cicatrix, or a shallow groove inclosed by walls with notched, 
tuberculated edges. (Atlas, Fig. 131.) 

The process of cicatrization experiences interruptions in con- 
sequence of diseases of the gum, socket or maxillary periosteum. 
Abscesses, especially, which have their origin in the root-mem- 
brane of a tooth, may be adduced with reference to this point ; 
these frequently spread over the alveolar process, give rise to a 
destruction of the bony substance and involve the gums and 
periosteum. Under such circumstances, the callus, particularly 
in the vicinity of the upper molar and wisdom teeth, becomes 



262 



ATROPHIES. 



distorted, spreads over a greater surface and is studded w,th 
irregular, flattened tubercles and corresponding depressions. 
The°pr° cess of ossification may even be arrested here and there, 
as is manifested by the abundant deposits of calcareous 
without evidences of further organization. Sometimes the ex- 







tremity of one or another of the roots remains inclosed. The 
submucous connective tissue of the gum - B »»> t0 a 

callous, cartilaginous, tuberculated tissue, and is intimal 
united with the felted, tendinous portions of the maxillary 
periosteum. 

Further, the process of cicatrization may be interr 
recurrent abscesses of the gum, or arrested by a pro! sup- 

puration in the bone; the pus, in some inst: ike 

its escape, but the cavity of the al ut in by the call 

connective tissue, becomes obliterated, and the pus is found 
transformed into an unctuous, caseous mass. The I 5 the 

tuberosity of the upper jaw, mentioned al the 

more frequent seat of such an arrest. (Atlas, 

* Fig. 80 shows a median section through the | 
jaw, together with the cicatrized sockets of the molar teeth. The in!' 
dental foramen is seen at (a); the interior dental canal is bisected il 
length; above and below the latter extends the spong; nee. 

The cicatrization is entirely completed : the alveoli have die 
towards the outer surface, a compact bony BtlbsUnce 
with the firm sharp-edged callus, has been formed. - : .ze. 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 263 

A fracture of the alveolus, if limited to the site of the ex- 
tracted tooth, does not interfere with the healing process unless, 
perhaps, an irritation of the contiguous gum is produced by the 
sharp edges or points, or loose spicula remain within the socket, 
which cause pain and give rise to suppuration that continues 
until the necrosed spicula are expelled, or removed by operative 
interference. At the part corresponding with the fracture, the 
cicatrix presents a more contracted appearance, and its surface 
is upon a deeper level. When, however, the fracture extends 
across the alveolus of an adjacent tooth with a permanent loss 
of the fragment, the socket is not reproduced and, as a result 
of this, the gum recedes and, consequently, the tooth becomes 
loose. 

With adults and those whose teeth are still firmly implanted, 
cicatrization occupies a period of three to six months, generalh', 
but it is by no means at an end when the cicntrix of the gum is 
completed, since the formation of the bony callus together with the 
resorption of the osseous substance in the neighborhood require 
months longer than the above mentioned period. The reverse 
is the case with teeth which have been quite loose, from the fact 
that, in proportion to their looseness, the bottom of their sockets 
have already become more or less filled with new osseous sub- 
stance and the alveolar margins have already undergone resorp- 
tion, so that cicatrization in these cases may be completed in a 
comparatively short period, sometimes in four to six weeks. 
Practitioners are well aware that the cicatrices are subject to 
variations in form for a long time subsequent to the extraction 
of teeth, since it is a frequent occurrence, that plates which 
have been adapted six months after the extraction of the teeth, 
become displaced in a few months and no longer occupy the site 
from which the teeth were removed originally. Casts of the 
jaw, taken at this latter period and compared with those of the 
earlier periods, also indicate, conclusively, the occurrence of 
changes of form. 

The subsequent variations in the position of the adjacent teeth 
during the process of cicatrization form a subject of consider- 
able importance. In order to obtain a thorough insight into 
this process, it is of advantage to remove either the facial or 



264 ATROPHIES. 

lingual wall from a series of macerated jaws in which the teeth 
are defective, in order that we may be able to obtain an accurate 
idea of the location of the respective root.-. 

The deviation from the normal position may be ex] 
general terms as consisting in an inclination towards the cicatrix 
of the crowns of the teeth adjacent to the latter, which deviation 
is most distinctly marked with the largest teeth, as the mo] 
It is exceedingly instructive to observe the difference in the de- 
viation presented in those cases where the teeth are defective 
upon one side only. If the coronal portion of one of thi 
named teeth is tilted forwards in consequence of th. 
the adjacent tooth in front, the anteri 
becomes depressed below, and the posterior i- raifl 
previous level, to a degree varying with the amount of the in- 
clination. The root portion necessirily experience 
ponding backward displacement and is 1 slight) 

81). In addition to the above approximation of th. 
tooth towards the horizontal line, an inclination of a 

Fig. 81.* 




grees towards the median line of the jaw. also, occurs, sometime^ 
indeed, the lingual wall of the crown of a wisdom 
experiences a slight rotation towards the median lin, 

rel^M . h ~f sht "f of • l0WCT J« f~m winch .he facial wall has been 
eccTA ? fZ '° ° Wth0 Wwil—tai of the second I 

lo s nrr , ' 0WardS CaCh ° tlK ' r Within the *oc 

ZJrlT 7 "■ , The crowus ■»• ; ' , " 1 °" in «»' 



MAXILLARY PERIOSTEUM AND MAXILLARY BOXES. 265 

teriorly. If the alveolar cicatrix occupies the place of three 
or four teeth, e. g., the two bicuspids and first molar or all the 
molars, that portion of the alveolar process which remains op- 
posite the angle of the lower jaw, together with whatever teeth 
are still retained, sink down, so that they occupy a lower level 
than the corresponding teeth upon the other side where such a 
defect does not exist. 

Inclinations of the wisdom and molar teeth of the upper jaw, in 
connection with the loss of teeth, are less marked, as a rule, and 
in certain respects, present relations the reverse of those pre- 
sented by the same teeth of the lower jaw; the anterior segment 
of the crown becomes raised, somewhat, the posterior, depressed 
to an equal degree, producing a greater or less dislocation of 
the posterior portion of the neck of the tooth from out the 
socket. Axial rotations are less liable to occur, from the fact 
that the corresponding teeth of the upper jaw are supplied with 
three divergent roots. The forward inclination of the second 
upper molar, subsequent to the loss of the first, may retard the 
eruption of the wisdom tooth in certain cases (comp. p. 129). 

Dislocations of the bicuspids are not so notable, in most cases, 
since they are held in their positions by the canine teeth which, 
as is well known, are the last to fall out in old age and are least 
liable to be affected with caries. When cicatrization of the 
socket of the first bicuspid takes place, the second bicuspid 
ises towards the canine tooth and experiences a slight axial 
rotation anteriorly and an inclination towards the median line 
of the jaw. 

Subsequent to the completion of the cicatrization of the socket 
of the lateral incisor, the central becomes inclined towards the 
canine, now and then with a slight rotation of its anterior coronal 
surface towards the latter tooth. If the incisors on both the 
right and left sides are removed, then the crowns of the retained 
canines become inclined towards each other. If a canine tooth 
is wanting, the lateral incisor is inclined in the direction of the 
cicatrix to a degree commensurate with the smaller bulk of its 
root in comparison with that of the canine. 

The changes of position, produced by alveolar cicatrices, 
necessarily have an influence upon the act of mastication which 



266 ATROPHIES. 

becomes variously modified ; the age of an individual, also, is an 
element of importance in this connection, for, with young per- 
sons whose jaws are not completely developed, the bony cicatrix 
frequently is so slight that scarcely any deviation of the con- 
tiguous teeth ensues, and their crowns frequently come into 
relation with each other in a normal position. 

Finally, the question arises, what influence does the extraction 
of the milk teeth exercise upon the development of the perma- 
nent teeth? The effect of cicatrization in tl. 
according to the age of the child and the kind of tooth. The 
older the child, the nearer is the period for the eruption of the 
corresponding permanent tooth, and so the latter will 

be expedited by the extraction ; on the other hand, when the 
milk teeth are extracted too early, a callus ifl 1 which 

retards the eruption of the permanent teeth and may d< : 
them from their normal course. The eruption of the permanent 
bicuspids is retarded, merely, by the thickening of the superficial 
portion of the capsule occasioned by the callus, but the incia 
and canines, according to their location with i the 

pre-existing milk teeth, may also be deflected from their normal 
course by the thickened alveolar wall in front or behind them. 

When, in old age, a marked wasting of the alveolar pr 
and sockets ensues, associated, frequently, with a chronic in- 
flammation of the periosteal membranes of the roots, the U 
which still remain gradually become deprived of their support, 
since the greater portion of the root* e denuded and 

merely their extremities remain fixed in the jaw. Tl.. 
consequently, acquire abnormal positions and become die 
towards the face or tongue, under the influence of mastica: 
(Fig. 82). 

With edentulous jaws of advanced age, the reverse relat! 
obtain with reference to the prominence of the jai ^. When all 
the teeth are present and properly located, the upper set pro- 
jects somewhat beyond the lower; but the toothless up] 
of old age recedes to such an extent that the toothless 
jaw projects considerably in advance of it 
pearance is to be explained in the following manner. The 
alveoli are deeper and occupy a greater extent of space in the 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 267 

abundant spongy tissue of the upper jaw, and therefore their 
cicatrices contract more and acquire deeper depressions, especi- 

FlG. 82.* 




ally those corresponding to the large cavities occupied by the 
molars with three roots, than is the case with the lower jaw, 



Fii.. 83.t 




* Fig. 82 show- marked displacement of the teeth of the upper jaw, the 
results of senile wasting of the alveolar process. Lateral view. The roots 
of the six remaining teeth arc almost entirely denuded, being attached, within 
the remains of the alveoli, at their extremities only. The right central in- 
cisor (a), which is worn away upon its incisive edge, has a nearly horizontal 
position. The crowns of the left central incisor (b), the axis of which is 
elevated at an angle of about 45°, of the lateral incisor (c), and the canine 
(d), diverge from one another. The left wisdom tooth (<?), and first right 
molar (/), present the least deviation from the normal position. The facial 
wall of the antrum (g) has become reduced to a transparent bony plate, as 
thin as tissue-paper ; the posterior segments of the palatal plates, also, are 
remarkably thin and transparent. The rest of the hard, bony portions pre- 
sent a yellowish color, induced by fatty degeneration. Two-thirds natural 
size. 

f Fig. 83 shows a view in profile of a toothless upper and lower jaw, from 
an aged person, in their natural position with respect to each other. The 



268 ATROPHIES. 

which is more compactly formed, for the attachment of its 
powerful muscles. The lower half of the face obviously dimin- 
ishes in length to a degree commensurate with the height to 
which the crowns projected from their socket.-, added to 
entire depth of the alveolar processes in the two jaws. The 
latter, seen in profile, form a re-entering angle in front, which 
occasions a retraction of the lips and the characteristic mouth 
of old age. 

The ridge, formed along the alveolar cicatrices after th< 
tachment or extraction of the teeth, gradually low arp- 

ness, becomes rounded ami. finally, flat, with inci 
especially upon the posterior segments of the lower j;iv. . 
the cicatrices acquire the form of a continuous, finely-d 
bony suture. The palatal pn :' the appei 

flattened and form a horizontal bony roof to the month, 
which and the facial wall the alveolar cicati 1 in 

the form of a blunt ridge. Transfers li>h the 

fact that flattened cicatrices undergo a prO| 
Their flattened portions towards the masticating Burf 
composed of compact osseous Bubstanc A millimi 

thickness, the outer surface of which pree 
notched appearance, occasioned by indent 
resorption. 

The cicatrices of the gums of senile, toothh char- 



resorption of the alveolar pr< mplete, to 

to a greater extent in the upper than in the low 
retracted to a considerable distance toward I 
alveolar edge of the upper jaw forms a curve, with 
downwards while that of the lower ja, 

The suture of the flattened palatal plates ot the u PP , . in the 

form of a ridge wasting of the bone having ensued 
~"ch the fatty Haversian canals are ap, 
wall of the jaw. The facial wall of the inferior ma, 
7 ! le W " tmg °l the b0ne > has u °dergone a dis, 
T^ecoronotr d ^ f « h -^ U ired a , 
The coionoid process ,s very thin, the neck of the arti 

";:l l he 7^[ tl '^-^he temporal.. 

quenc of the loss of all the teeth and the wasting of , 
Iwo-tlnrds natural size 



MAXILLARY PERIOSTEUM AND MAXILLARY BONES. 269 

acterized by a very dry, callous condition: frequently, also, they 
present ridges of a cartilaginous consistence, composed of de- 
generated connective tissue, and often contain one or more 
roots which may be the source of irritation and subsequent ab- 
scesses. Bundles of tense fibrous tissue extend from the peri- 
osteal layer of the gums between the serrated bony margins of 
the cicatricial substance, and are intimately united to them. 
Whenever an irregular groove remains in consequence of a want 
of junction between the bony substance on either side, it is alsb 
found to be filled with firm fibrous tissue. 

. In old age, the angle of the lower jaw becomes more obtuse, 
resembling, therefore, that of the infantile jaw. This change. 
as Hunter has shown, is occasioned by resorption of the bone at 
the angle, as is indicated to the touch by the rough surface, and 
this process takes place in a manner essentially similar to that 
already described in connection with senile cement. The in- 
dentations produced by resorption upon the surface of the latter 
are, generally, small, and, on cross-section, present irregular, 
festooned borders; on close inspection, however, deeper, dome- 
shaped concavities may also be found, and even proliferated, 
young, osseous substance, as is the case upon the cement of the 
milk teeth at the period of dedentition or upon senile teeth. 
Bone-corpuscles, inclosed within a capsular investment, also, 
occur ; hence, development and resorption of osseous tissue are 
presented side by side. This peripheral is succeeded by a, peri- 
cellular resorption upon the interior of the cancelli or medullary 
spaces of the bone which, in cross-section, instead of the finely- 
indented margins produced by the openings of the bone canali- 
culi r present the segments of indentations of resorption in which 
the usure of the bone-corpuscles is apparent. The periosteum 
and endosteum [medullary membrane] are transformed into a 
tense, firm, fibrous mass. 

The masseter and internal pterygoid muscles which are at- 
tached to the angles of the lower jaw participate in the senile 
wasting of the tissues, as is indicated by a diminution in the 
quantity of the muscular substance, its pale color and great fri- 
ability, by the fatty metamorphosis of the muscular fibrillre and, 
sometimes, by an abundant multiplication of fat-cells between 



270 ATROPHIES. 

the primitive muscular fasciculi. The movements of mastication 
are performed with diminished energy. 

The wasting of the coronoid process and condyle of the lower 
jaw is quite marked; the circumference of the articular head of 
the condyle is diminished, and its surface presents nnmer 
small bony excrescences, as the cartilaginous investment is de- 
stroyed. 

The flattening of the articular eminence of the temporal bone 
exercises an influence upon the act of mastication to which 
Thomas Bell* alludes as follows: "In children the area of the 
articular cavity for the lower jaw _ ter than that 

of the condyle; the articular eminence ifl do! yet Formed. The 
movements consist simply in raising and di the 

least approach to the rotation of the jaw. In fact, the condyle 
is the centre of movement. With old people 
all their teeth, the lower jaw is simply moved up and down. 
the teeth are absent, it is only necessary . the mouth 

slightly for the reception of food.'' 



.p. 51. 



CEMENT. 271 



IV. HYPERTROPHIES. 

The augmented nutrition of any organ requires an increased 
supply of nutritive material from the bloodvessels which either 
enter the organ directly or, without entering it, effect the in- 
terchange of materials by their close proximity to it. An 
increased supply is rendered possible by increased contractility 
of the bloodvessels, and subsequent thickening and dilatation 
of their cavities. A continued irritation of the nerves involved 
accompanies this process. In hypertrophy, the elementary 
organs assume an unwonted activity ; they increase in volume 
and proliferate more largely than usual. While they manifest 
augmented productivity, their development is frequently arrested 
at an embryonic stage. 

If, now, a greater amount of formative material is excreted 
from the blood than can be appropriated, the accumulated mate- 
rial must necessarily undergo a retrograde metamorphosis, or 
the reverse may occur, the multitude of elements which are pro- 
duced may be insufficiently nourished by the formative material 
with which they are supplied, and, therefore, a portion of them 
are destroyed. 

In true hypertrophy, the elementary organs are identical in 
quality with those originally belonging to the part ; their de- 
viation from the normal condition has reference, for the most 
part, merely to the stage to which their development attains, 
and to their disposition, because the ordinary relations of con- 
structive and destructive metamorphosis are altered. We have 
to consider hypertrophy of the cement, periosteum of the root, 
and gum, true hypertrophies of tissues belonging to the cate- 
gory of connective substances. 

Cement. — Hypertrophy of this tissue occurs along with hy- 
pertrophy of the periosteum of the root, since it is induced by 
a chronic irritation of the latter membrane. Various modifica- 
tions are distinguished which present transitions from one into 



272 HYPERTROPHIES. 

another, several of which sometimes occur together ; tie 
based upon the disposition and form of the bone-corpusch 
basis-substance, the occasional vascular canals, the interstitial 
development of new osseous tissue, and the retrograde meta- 
morphosis. 

With reference to the external form, a cap-shaped var: 
distinguished, in which the hypertrophic cement 
the greater portion of the root, or in vesta it completely 
as the neck of the tooth, becoming gradually am-?, 
the non-hypertrophied portion. Nodulated, tnbercalated, warty 
forms are designated, commonly, a- s, and will b<- 

sidered in connection with the Bubject <>t* new-formati 

When viewed with the lens, the outer Burface of hyj 
cement is seen to be marked with shallow pi I 
which are attached, generally, the remnants of I 
of the root. Its color is rather light, frequently inclini 
white, and is quite conspicuous, particularly 
teeth of elderly persons. The apertures :it the apices of the 
roots, which serve for the transmission of the dental d 
bloodvessels, are often diminished i: I by a 

growth from one side. Sometimes, rtures 

are found, and in such cases, it is easy t«» m 1 that the 

dental nerves are bent from their course, lac 
upon by the bony substance which is develo] 
tremity of the canal; the branches, likewise, which an 
tributed to the periosteum of the r ' -. 

previous to the entrance of the latter into the dental 
displaced by the abnormal local relations, and th< nally 

severe neuralgias consequent upon these conditions may I 
plained by the unusual tension to which the nerves 
jected. 

As a general rule, it may be said that the occurrence 
rare upon the front teeth; occasionally, however, 
ally the upper ones, present a notable hypertrophy, 
shaped variety is observed more frequently upon the 
cuspids (Atlas, Fig. 100), and next in frequency it occurs upon 
the wisdom teeth with blended roots (Atlas, Fig. 1 
quently, also, it is found upon the anterior facial roots of the 



CEMENT. 273 

upper molars. Sometimes, both facial roots are united by ce- 
ment, and, in quite rare cases, the apices of the three roots are 
united by a hypertrophic growth (Atlas, Fig. 102). Now and 
then, the hypertrophy is confined to the contiguous surfaces of 
these roots (Atlas, Fig. 103). Upon the extremities of the 
roots of the lower molars, it forms a rounded knob. 

Upon close examination, it will be seen that in some places 
tolerably uniform intervals are preserved between the bone-cor- 
puscles, the long diameters of which are disposed horizontally, 
i. e., are perpendicular to the axis of the tooth or have a direc- 
tion parallel or at an oblique angle with the latter, and in other 
places they are crowded together or are situated far apart. 
The former relations are observed more particularly in concen- 
tric hypertrophies (Atlas, Fig. 10G), in which numerous layers 
of cement encircle the dentine in a manner similar to the annual 
rings in wood. Generally, however, this lamination is limited 
to certain localities, while in others an excessive proliferation 
occasions clusters of numerous bone-corpuscles and, occasion- 
ally, cross-sections, especially, present elongated, isolated layers 
of densely packed bone-corpuscles, the canaliculi of which must 
have suffered an arrest of development. Frequently, the bone- 
corpuscles attain quite large dimensions, are abundantly sup- 
plied with canaliculi, which are of considerable length and fur- 
nished with anastomotic loops ; smaller bone-corpuscles are 
sometimes attached to the sides of the larger ones, or are blended 
with them; large and small ones also occur separately. When 
they are separated by very wide intervals, the intervening 
canaliculi are nearly parallel with one another, resembling in 
this respect, the dentinal canals, or, in some instances, are want- 
ing, and the intervals are occupied merely by a finely-granular 
basis-substance. 

Sometimes, peripheral resorption takes place in hypertrophic 
cement which, then, has a rough exterior and presents a serrated 
appearance in cross-sections (Atlas, Fig. 116). The appear- 
ances produced by this process are not uniform in character, 
for, at one part, the cement layers may be affected but slightly, 
and at others the resorption may induce a total destruction of 
them and even involve the dentine, and, in many places, it oc- 

18 



2U 



HYPERTROPHIES. 



cations a circumscribed or localized breach of substance (Atlas, 
Figs. 98 and 106). Again, especially upon the roots of carious 
teeth, it attacks the peripheral layers of the cement at many 
points and involves the entire thickness of the latter I 
and even of the dentine, as far as the cavity of the root, its 
course being marked by rough channels, It is induced 
proliferation of the connective-tissue elementary if the 

periosteum of the root, or suppuration, and is called j 
resorption (Fig. 84). 



Fig. M* 




Interstitial resorption of hypertrophic cem< 
the form of cavities of which several n 
Some of them present radiating canaliculi, and 1 
the results, apparently, of the resorption of adjacent bon< 
puscles, while, in others, these canaliculi ar< 
vacuities, also, are met with of various dim. 



■ Fig. 84 shows the results of resorption which extended from without in- 
wards, in places even as far as the pulp-canal, upon the r 
molar with hypertrophic cement. The resorption I 
shaped excavations (a,, and occasionally bifurt 

\ V eiT Wide flask " sha P ed c »"t y> only half of whi 

in the figure (c), extends through the entire thi : ;t *nd 

dentine, as far as the wall of the dental canal which, li 
(usur.rt) to a certain extent. Minute examination i 
made up of indentations which arc lined with , 
80 diameters. 



CEMENT. 2iO 

some present annular constrictions, while others occur in the 
form of flask-shaped expansions which terminate, frequently, in 
narrow necks, present lateral cavities and are filled with amor- 
phous calcareous salts, fat-granules, dirty yellow pigment, or a 
fluid. As a rule, they are met with most frequently in the older 
layers of cement adjoining the peripheral globular layer of the 
dentine, where they form, sometimes, irregular, elongated cavities 
from which processes extend far into the dentine. They may 
arise in various ways. Where several adjacent bone-corpuscles 
undergo resorption, the canaliculi which radiate from the cavity 
that is formed are destroyed as the latter expands. The pene- 
tration of bloodvessels into the cement frequently occasions a 
resorption of the corresponding portion of the latter, and the 
former may be obliterated and become transformed into vacui- 
ties or channels containing calcareous salts and the products of 
fatty metamorphosis. Another form of interstitial wasting con- 
sists in a granular disintegration of the intercorpuscular sub- 
stance which acquires a color varying between dirty-yellow and 
brown. Portions thus affected pass imperceptibly into the neigh- 
boring tissue, and in them the outlines of the bone-corpuscles are 
still recognizable, except at those parts where the degeneration is 
very extensive. These instances of resorption which have been 
described are met with most frequently upon carious roots. 

The vascular canals, which are of frequent occurrence in hyper- 
trophic cement, penetrate from the outer surface, give off lateral 
branches or, perhaps, form a network of ramifications and extend 
as far as. and even into the dentine and, generally, they form an 
oblique angle with the latter and are tolerably uniform in size. 
It is a peculiarity belonging to them that their sheaths undergo 
an extensive calcification which, ultimately, occasions an oblit- 
eration of their cavities. Hence, elongated channels, filled with 
calcareous granules, are met with (Atlas, Fig. 105), the hollow 
nature of which is indicated by cross-sections and, also, by sec- 
tions in which the channels are presented in their length, by 
the presence of air in portions which have become emptied of 
their contents. The vessels do not completely fill the channels, 
have thin walls, comparatively wide cavities, generally termi- 



276 HYPERTROPHIES. 

nate with closed extremities and, only exceptionally, contain 
blood. 

The vascular canals sometimes are surrounded by a substance 
which forms an investment of variable thickness and i> 
rated from the basis-substance by a brighter boundary lay 
presents a notched, sharply defined border, a radiated, granular 
structure, and is to be regarded as an external limiting lav 
rudimentary osseous substance (Atlas, Fig. 105 ; for, when 
traced in its further progress, groups of young bone-corpuscles 
have been found imbedded within it. Hence, there is presented 
a development of new osseous substance around the vascular 
canals, and it may be traced even as far as the border of the 
dentine. 

Finally, bone-corpuscles are met with beneath the outer sur- 
face of hypertrophic cement, in the intermediate portions or 
even in the vicinity of the dentine, which, cither in pairs or in 
groups of three or more, are encapsulated by an indented highly 
refractive layer and present an appearance as if they were in- 
serted within the proper layers of cement. The young corpus- 
cles, sometimes, inclose a distinct cellular body t g pritfa a 
nucleus, and multiply by a progressive segmentation ; generally, 
but few canaliculi radiate from them, and these unite with the 
adjacent canaliculi in the same group, while they do nofl 
with those of the concentric laminae of the cement, at off 
by the capsular layer. 

A tivofold hypertrophic growth of a m nt must, therefore, be 
distinguished, namely, a peripheral con.. .forms 

to the disposition of the pre-existing layers, and an u 
intercalated hypertrophy. The latter, probably, is 
about by the penetration of the branches of the periosteal I 
vessels into the cement. I have generally found sue!. 
upon cement in which numerous vascular* canals have been de- 
veloped and, also, in the hypertrophic cement upon the teeth of 
the hippopotamus, horse, cattle, lama, and stag. It cannot, 
however, be said that a vascular canal occurs in all cases where 
groups of young bone-corpuscles are developed ; iris much more 
reasonable to assume that the formative material which induces 
the resorption of the old and out of which the nc a sub- 



ROOT -MEMBRANE. 277 

stance is developed, may permeate to a certain depth. The cir- 
culation within the canals of the hypertrophic cement is quite 
imperfect and represents an embryonic stage, since canals, with 
closed extremities, are met with very often, and only excep- 
tionally do we find a plexus; indeed, the reason for the prema- 
ture calcification of the canals is to be sought for in this defec- 
tive development. 

The osseous growth not infrequently extends beyond its 
proper limits and encroaches upon the dentine. Cases occur in 
which single bone-corpuscles or groups of them have displaced 
the dentine, being separated from the latter by a hyaline, 
notched, limiting layer. A similar occurrence has been referred 
to before (Atlas, Fig. 110),* in connection with the resorption 
of the roots of the milk teeth during dedentition, and we can 
explain it only as an instance of interstitial growth of bone. 
The vascular proliferations, which frequently penetrate deeply 
into the dentine, sometimes are invested with a layer of rudi- 
mentary osseous substance containing bone-corpuscles which 
are stunted in their development, as may be demonstrated in 
the interior of the dentine by means of cross-sections. Deep 
funnel-shaped prolongations of the cement-substance into the 
dentine (Atlas, Fig. 109) are met with in a few cases. It is 
quite common to find hypertrophy of the cement in combination 
with a new growth of osseous substance upon the surface of the 
canal of the root, which becomes lined by it, in some cases, for a 
considerable distance from the extremity. 

Root-membraxe. — In addition to the senile form, an hyper- 
trophy occurs as a sequel of chronic affections of the root-mem- 
brane, consisting, essentially, in a thickening and a more or less 
advanced callous formation. In order to investigate this sub- 
ject, detached preparations are employed and also cross-sections 
which, perhaps, it is unnecessary to add, should only be made 
upon decalcified portions of the jaw containing the corresponding 
roots, and all the more from the fact that there is a question 
respecting the connection of the periosteum of the root, on one 
side, with the root, and, on the other, with the alveolus. The 

* Comp. p. 78. 



278 



HYPERTROPHIES. 



generally straight bundles of fibrous tissue often pursue a radia- 
ting course for the most part, i. e., they extend from the outer 
surface of the cement, towards the alveolar wall, form ies 

of closely-packed arches, and are inserted, by a fan- ex- 

pansion, into the osseous trabecule. During their | -he 

bundles inclose spaces which, likewise, are traversed by thin 
bundles. These are the depositories for the aggr< 8 of 

ovoid cells which, here and there, form radiated pr a tions 
to the cavities, their number bearing an inverse pr I to 

the density of the thickened periosteum. Besides tter 

cells, and more nearly in the course of the bundles, spindle- 
shaped cells occur which have oblong, frequently fibre-like, 
elongated nuclei. 

The bundles of connective tissue, especially in i 
irregular hypertrophy, interlace with one another in var. 
directions, forming a sort of felted work of bandies which 
penetrate the enlarged foramina in the alveolar wall, 
sections of periosteum of this description present, tl 
numerous protuberances and conical prolongations 
In consequence of the increase of the tibrillated I the 

periosteum, its consistence becomes augmented and it may i 
acquire a tendinous character, so that its ten. 
quent power of resistance in extraction are inc 

The fringes presented by the membrane when • 
along with the root are, manifestly, pulled out from the vascular 
foramina of the socket and consist of cloudy tough bundles 
connective tissue, containing numerous, usually Bhri veiled in 
and inclosing bloodvessels with their external inch 

thickened. They form an intimate, quite firm union 
the root-membrane and the socket, in eonsequen rhich 

fragments of the alveolar wall, particularly th 
which correspond with the neck of the tooth, are very liabl 
be removed along with the tooth, in the extraction of the latter. 
Elastic fibres do not occur in the sclerotic periosteal mem- 
brane. The nerve-branches are so concealed fron the 
fibrous connective tissue that they cannot be identified until I 
are cleared up by treatment with the proper n The 
nerve-tubes are filled with a mass of diminutive 



gums. 279 

and present an appearance similar to that found in senile atrophy 
of this memhrane. Here and there, the bloodvessels are isolable 
in short segments and, in places, are obliterated. The veins 
are considerably dilated in some cases, and form a network 
with large meshes (Atlas, Fig. 122). 

Fig. 




b ~ 



Deposits of pigment occur in the callous root-membranes and 
may be seen with the naked eye in the form of diffused specks 
of a dark-brown or reddish-brown color, or of various shades 
between the latter and a grayish-black. It may be assumed, 
with good reason, that these originate from previous extrava- 
sations of blood, from the fact that blood-corpuscles, deprived of 
their coloring matter, are frequently met with in connection 
with the interposed pigment molecules. 

Gums. — Hypertrophy of the gums occurs frequently among 
the sequelae of a chronic inflammatoiy condition of the root- 

* Fig. 85. — Proliferation of the straight connective tissue in the periosteum 
of the root of a carious upper bicuspid. Cross-section. The fibrillated bundles 
of connective tissue encircle the root of the tooth in more or less parallel 
layers (a) and, also, form small concentric lamellae which evidently corres- 
pond to the proliferations of the fibrous sheaths of the bloodvessels and 
penetrate more or less deeply into, and fill, the medullary spaces of the 
upper jaw (b). At this part the alveolar wall has disappeared under resorp- 
tion and the lamella?* of the spongy tissue of the bone (c, c) have been dis- 
placed by the proliferating connective substance. With higher magnifying 
powers, the familiar erosions resulting from resorption may be seen upon 
the margins of the bone. Magnified 80 diameters. 



280 HYPERTROPHIES. 

membrane following caries of the teeth, and is induced, ale 
the irritation of the gums produced by the products of the de- 
generation of the hard tissues of the teeth. The sharp edg 
stumps, too, which remain after the destruction of the coronal 
portions and necks of the teeth, become the sources of irritation. 

The hypertrophy occurs both in the papillary portion and. 
beneath the latter, in the cerium of the mucous mem' 
When it occurs in the former, it is most conspicuous upon the 
facial surface of the gums and is confined to the a f f »ne 

tooth or a few teeth, or acquires more extended limit! 
of caries involving the crowns or roots i th. 

While the papillae occur in clusters in the -normal state, in 
the hypertrophied condition, the manner in which they are 
grouped together becomes much more evident. Th< 
smooth, pale or reddish, clavate, conical pi 
millimetres in length and attached 
are confined to the region of the gm 
as the alveolar process and, consequently, j 
outline when viewed together (Atlas, Fig. 118). Fi 
the hypertrophic condition becomes less marked from tie 
gival border towards the commencement of the alveolar pi 
while, in the opposite direction, it is prolonged into the intervals 
between the teeth and becomes visible upon the lingual surface 
of the gum in the form of tumid protul | with 

thick epithelial layers. Papillary proliferations, in tl 
developmental stages, give to the gums a velvet J app 

Each of the above-mentioned conical proje 
of a group of hypertrophied papilla* which B y nu- 

merous layers of flattened epithelium common to them all, 
are not distinctly visible until after the removal 
The groups are separated from one anothi sis of 

varying depth, and include a larger (ten to 6 - taller 

number of finger-shaped papilla which, usually, an times 

larger than in the normal condition (A: 
of the hypertrophied papilla* present a distended a P] 
with an irregular outline, others lateral or terminal eic i 
or buds, which indicate a continued growth; they contain in 
their interior a continuous vascular loop: tl - Is in 



GUMS. 281 

them frequently pursue an irregular, distinctly wavy or spiral 
course, divide dichotomously and form a network ; they are 
considerably dilated, the recurrent capillaries more particularly, 
and frequently are filled with a homogeneous, colloid mass. 
Fine elastic fibres occur in considerable abundance. If marked 
cellular infiltrations into the corium of the gums occur, they 
also extend into the papillae and along the capillaries. The 
parenchyma of the papillae, in consequence of nutritive disturb- 
ances, sometimes acquires a clouded appearance, has a dirty- 
brownish color, or is interspersed with numerous fat-globules. 

The epithelium, also, participates in the hypertrophy which 
affects the papillary portion; the nuclei swell up, the nucleoli 
become more prominent ; occasionally a double nucleus is met 
with. The groups of papillae are covered by the cells of the 
horny layer, disposed in Beveral layers common to them all and 
having a slightly wavy outline. The cells of the mucous layer, 
likewise, are increased in number ; their protoplasm frequently 
presents a molecular cloudiness; they invest the individual 
papillae, between the groups of which they form conical prolon- 
gations, extending, in many cases, to a considerable depth into 
the corium. 

It is found, also, that the papillae increase in length and thick- 
ness and, also, by the development of lateral processes; in place 
of a simple hypertrophy, therefore, there succeeds a new-forma- 
tion of papilla, a papilloma, which, in its general form, resem- 
bles the acuminate condyloma. Contemporaneously with the 
growth of the papillae, the bloodvessels, also, increase in length, 
become wider in parts, and give off branches by means of which 
a plexus of capillaries is formed. The nerves do not appear to 
participate in the process. As the dimensions of the papillary 
portion increase, the separate laminae of epithelium, also, become 
augmented, the proliferation of the cells of the mucous layer 
being especially notable. The development of the latter and 
that of the papillae take place in opposite directions, namely, 
that of the papillae towards the free outer surface, and that of 
the cells of the mucous layer towards the corium. 

The hypertrophic corium of the gum is infiltrated with cells 
which frequently are disposed in rows and in part accompany 



282 HYPERTROPHIES. 

the bloodvessels and nerves so that they form a meshed work, 

in the bright vacuities of which connective-tissue cor 

united together so as to form a network, are visible | Atlas, 

IV. 119). Moreover, a proliferation of ovoid and : 

elementary organs of the connective tissue, at a distance from 

the bloodvessels and nerves, is also observed. These cellular 

infiltrates sometimes are bo extensive as nearly to fill the corium 

layer in places, and to occasion a notable tumefaction and suc- 

culency. These products of proliferati 11 as the 

of a higher order of development, frequently and _ tro- 

grade metamorphoses, become the Bubject of fatty d tion, 

pigmentary deposits, shrinking, colloid n, the lal 

being presented in the form of minute, cloddy In the 

deepest layers of the mucous membrane, in the submucous 

nective tissue, quite extensive zon< - 

with, or even groups of fat-cells, though I hav< 

any very marked proliferation of the latter; hen md, 

occasionally colloid or jelly-like formation- and, 

mentary, brownish-yellow mass 

That portion of the hypertrophied gum which e.v 
the teeth sometimes presents a lamellar development, with 
superposed, enlarged, papillary elevations, while the mm 
layer of epithelium dips down to a considerable depth 
the lamellae. 

The secretion of mucus usually is increased in connection with 
papillary hypertrophy, and partial exfoliations of the epithelium 
occur, leaving superficial erosions. Bleeding readily - rom 

the painless swellings, even from Blight mechanical irril 

Sometimes the papillary portion is not involved and the pro- 
liferation is confined to the corium. occasion i 
the gum, which has a smooth exterior. In t; 
are more protracted, the cellular infiltrations give I 
dinous connective tissue; in other words, the hypertrophic gum 
becomes sclerosed, and, consequently, it prei 
power of resistance and a diminished succuleney. The gradually 
obliterated papillary portion is covered by a common, tl 
superficially smooth layer of epithelium. Notwitha 
increased consistence of the corium, cellular infiltra a 



gums. 283 

with in the form of long chain-like rows or clusters of ovoid 
cells, which are inclosed within a capsule of fibrous tissue. Since 
the periosteum, also, beneath the indurated gum is thickened, 
it is by no means strange that cross-sections of the latter some- 
times present slender trabecular in the process of growth, to- 
gether with young bone-corpuscles. In very marked callosities, 
such as are presented so frequently in alveolar cicatrices, the 
tense fibrous tissue contains between its bundles cells which, 
for the most part, are shrivelled and present a granular cloudi- 
ness; the obliterated portions are indicated, principally, by a 
speckled, cloudy appearance, the nerves being shrivelled up and 
the bloodvessels obliterated. But, even in cases of marked in- 
duration, groups of well-formed, apparently vigorous cells, which 
still retain their germinal properties, arc met an ith. 



284 



NEW -FORMATIONS. 



V. NEW- FORMATION 

It is not possible, in all cases, to draw a line 
formations and hypertrophies, so that many of the 
only be described as localized hypertrophies. In ■ 
tion, the proliferation originates in one textur;. 
organ and spreads within certain limits, displaci _ 
in its progress the normal elements. The prolif 
not of a parasitic nature, that 
already formed tissues, as nutritive material, but, 
reabsorption of them. The more rigorous, 3 
older, enervated cell, whether it is a horn 

gous elementary formation. The young »»- 

creased productivity, supplant the 6\ 
tion premises an increased vitality 00 the 
vessels, together with proliferation of tin- 
destined to convey nutriment to the prolif 
augmented supply of blood which is there 

tates in turn an increased cell-formation in the par: h it 

is distributed. The vascular Bystem take> a prominent part in 
the production of a new-formation, whether the C 
which forms the framework of an organ, alone pal 
the elementary organs, which govern the function of a: 
also share in the process. The ti>sue ^ the org - the 

subject of an excessive growth within the affected lin 
also, of a corresponding alienation. The nerv l im- 

plicated only secondarily and. in exceptional cases, only, apj 
to take a prominent part in the process. 

New-formations occur in the hard and soft I 
and are only few in number, while the contiguous 
ticularly the jaws, present a very great variety, a kno* 
which comes within the province of dentistry and 
to the practical dentist, since the opportunity is frequently 



pulp. 285 

afforded to him, first of all, to diagnosticate them and to give 
timely advice with regard to operative interference. 

Pulp. — New-formations of the pulp have their origin either 
in the germs of the connective tissue or of the dentine. The 
parenchyma of the pulp can only be the seat of an increased 
productivity when there is sufficient space to allow the necessary 
increase in volume; such a condition is impossible so long as 
the pulp-cavity remains entirely encompassed by dentine, and 
can only occur when space is provided by the destruction of a 
portion of the wall of the cavity. 

When the new-formation has its origin in the dentinal germs, 
the circumstances are different; either the already-formed den- 
tine or the pulp-tissue becomes displaced, and is replaced by a 
newly formed hard structure. 

If caries has destroyed a portion of the wall of the pulp-cavity 
and the corresponding segment of the pulp is denuded ; if the 
individual is young in age; if the irritation of the pulp is mod- 
erate in character and there is no purulent destruction; if, 
besides, the local relations of the carious tooth and the locality 
of the caries in the tooth itself are such that the proliferating 
substance is protected against mechanical injuries, there arises 
upon the pulp, and projecting more or less beyond the perforated 
carious portion, a soft secondary formation with a rounded outer 
surface which is covered, frequently, with a layer of muco-puru- 
lent matter. Such a formation, usually, is described as a polypus 
of the pulp. 

The new structure may acquire about the size of a small pea, 
sometimes has a bluish-red color, at others is flesh-colored ; it 
is of a spongy or fleshy consistence, not sensitive to the touch, 
nor when slightly pricked, and is organically united with the 
coronal and radical portions of the pulp. It contains an abun- 
dance of roundish and spindle-shaped cells, the bodies of the 
cells varying slightly in extent, which, together with a small 
amount of fibrous intercellular substance, compose the principal 
portion of the tumor (Atlas, Fig. T9). The groups of cells 
are in long rows and have a radiated arrangement. The cells, 
which are provided with processes, unite here and there to form 
a network ; rows of spindle-shaped cells, also, are met with. The 



286 NEW-FORMATIONS. 

bloodvessels pursue a tortuous course from the interior towards 
the periphery, are numerous, comparatively large, and inreef 
with thick, fibrous sheaths. The type presented by the capil- 
lary ramifications is different from that found in the pulp. 
Nerves or remains of the parenchyma of the pulp are not to be 
seen. I have never observed an epithelial coverii a the 

outer surface. Occasionally, a purulent infiltration occurs in 
the vicinity of the latter and the blood xtend qui 

to it, so that hemorrhage is easily prodm 

The parenchymatous connective tissue is the seat of the pro- 
liferation described as sarcoma of the pulp, in which the paren- 
chyma gradually is destroyed, as is indicated by tl. 
nerves and the altered character of the bl J. Aj the 

sarcoma is located upon the outside of the dp, 

it serves in a measure to protect the latl 

New-formations of the Hard T : n. — 

These were first recognized by the an - <>f the \ 

century, and have occupied the attention «»f del 
logical anatomists of recent time-. < »{' lafc tanifold i 

troversial opinions have arisen res] their clii _ ilfi- 

cation and importance. f 



* Salter (Des pulpo-dentaires, Archn I 
classes: 1. Hypertrophy of the pulp in which tl.- 
ture, which retains its normal sensibility i 
pain. This he never found in carious teeth an . 
fractures. This class obviously does not b) 
but rather to the cicatricial formations. 2. In I 
sensitive and occurs in connection with car: 

generally in the molars of young, weakly f< tumor 

acquired quite large dimensions and corresponded b th the 

gum ; superficially there was a thick layer oi' p< Is. be- 

neath which were small, irregular papilla I: 
might easily have been confounded with a turn. g im. 

f J. Hunter (Nat. History of the Teeth dev. ,ph to 

these, in which it is shown that, in teeth which are worn ai rition. 

that portion of the pulp-cavity, adjacent to the abraded - 
filled with a new substance which occupies the 
face and, generally, is softer than the rest of th. 

chaska (Adnotat. academ. Prag. 1780) treated of tl, in his 

observat. anatom. de decremento dentium oorp. humani. I 
naire de medecine, article dent., 1835), gives a good de, 



NEW -FORMATIONS OF HARD TISSUES OF TEETH. 287 

A new-formation of the hard tissues of the tooth cannot be 
produced except from their formative elements, and since those 
of the enamel wholly disappear when the formation of the crown 
of the tooth is completed, it follows that the new-formations are 
limited to those of dentine and of bony substance. In these 
new-formations, the dentinal cells play the principal part, as in 
the formation of ordinary dentine, while an accessory or inde- 
pendent new-formation of bony substance alone is produced 
from the connective tissue of the parenchyma of the pulp through 
the medium of its bloodvessels. 

The new-formations which are to be taken into consideration, 
are located upon that surface of the body or root portion of the 
pulp which is directed towards the already-formed dentine, 
in the parenchyma of the pulp, or are imbedded in the sub- 
stance of the dentine. Hence, many varieties may be distin- 
guished. According to their situation they are parietal, ad- 



formations, which ho divides into two classes, the adherent and unattached. 
iid no attention to their histological structure; their connection with 
the pain in man j of the cases cited may he doubted. Other writers (ride 
11. Bohl'a Monographic fiber Neubildungen der Zahnpulpe, 1868), as Rous- 
seau, Nasmyth, Bertin, Raschkow, and Ryding, met with these hard forma- 
tions both in human teeth and in those of animals. R. Owen (Odontog- 
raphy) illustrates numerous new-foruiatione of osteo-dentine, but doe. riot 
go very deeply into the Bubject. Baiter (Guy's Hospital Reports, ix) treats 
of osteo-dentinal formations in addition to simple calcifications of the pulp, 
calcareous granular deposits. He regards them as the result of a pathologi- 
cal process. We are indebted to J. Tomes (A Course of Lectures on Dental 
Phys. and Surgery, 1848) for their first minute anatomical description, and 
to F. Ulrich (Zeitschrift der K K. Ges*Uschaft der Aezte zu Wien, 1851), 
who distinguishes in them two kinds of tissues, a dentinoid, an osteoid, and 
a combination of the two. Wedl (Grundzuge der pathol. Histologic, 1854), 
Heider and Wedl (Deutsche Vierteljabrsschr. f. Zahnheilk., 18G-4),give fur- 
ther anatomical details, and the latter endeavor to determine the mode of 
development of these new-formations. R. Hohl, in the work cited above, 
furnishes a critical treatise (18G8), based upon independent investigations, 
and applies to these formations, the terms odontoma, osteoma, and osteo- 
odontoma. Many writers have described the dentinal new-formations as 
odontomata, but.since this term has been selected to designate certain dental 
malformations, it is inadmissible to apply it to a new-formation of dentine, 
and, therefore, a distinction must be made between the odontomata occurring 
before and after the completion of the development of the tooth, namely, 
odontoma congenitum and acquisitum. 



288 NEW-FORMATIONS. 

herent to the wall of the pulp-cavity, or external ; free or in- 
ternal; and interstitial or imbedded in the dentine; according 
to their number they are single or multiple; in form they are 
flattened, round, wedge-shaped, conical, berry-like, warty, at- 
tached by means of a pedicle to the wall of the pulj - 
with respect to their position, they are located upon the wall of 
the pulp-cavity towards the masticating surface, upon its rad 
or lateral wall, and fill, more or less, the pulp-cavity or root- 
canal; with reference to the period at which they an- develo 
they maybe premature or senile; in respect of their 
they are consecutive, engendered by ex tenia 1 <• 
neous, and in size, they are very small, or may fill nearly the 
entire pulp-cavity or root-canal. 

A fine specimen of new-formation of dentine in the pulp-cavity 
or root-canal presents to the naked eye a yello* 
a certain degree of transparency, and a hard d to 

that of dentine. The exterior, invested by the pulp-tis 
has a rounded outline and, general: lulated. 

Their structure varies according to the circun 
which they are developed. Jf, from a new-formation of dent 
which has arisen subsequently to the abrasion «.f th< 
is perceptible upon the abraded Burface as a i 
rounded by polished dentine, section- through the 
tion, perpendicular to the abraded surf 

be found that the new hard substance is more transparent tl 
the original dentine, that the new canals extend in a radial 
manner towards the old and preserve, essentially, I di- 

rections as if they were central prolongations of the latter. In 
most places, there is observed proportionately rapid diminut 
in their transverse diameters, and an insertion of their t« 
continuations between the old, wide canals; in many 
therefore, there is no communication between tlu 
canals whde in others an immediate transition of the new into 
the old canals may be identified. From these h 
that, m these cases, there occurs a continued development of den- 
tine within certain limits determined by an irritation, and th 
the new layers are deposited in immediate contiguity with the 
old and, m parts, are intimately and organically united with 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 289 

the latter. Dentine of this description, which serves as a pro- 
tective covering of the pulp, is called dentine of repair, sec- 
ondary dentine (Ersatzdentin), as is that dentine, also, which is 
formed in cases of chronic caries upon that portion of the wall 
of the pulp-cavity corresponding to the carious locality and 
projects into the carious cavity in the form of a spherical seg- 
ment. In the latter cases, also, we find that the new dentinal 
canals are continuous with the old; there is, usually, an abundant 
basis-substance, and the canals are separated by quite wide in- 
tervals. Frequently there is a want of uniformity in develop- 
ment; for instance, the continuit}' of the dentinal substance Is 
interrupted by small and quite large, elongated, jugged cavities 
which are filled with amorphous calcareous suits. Some of 
these are the results of resorption, similar to tl. rved fre- 

quently in senile dentine, and others are interglobular spaces 
(Atlas, Fig. 72). The less compact structure of the new den- 
tine is due to the 

A different structure is presented by the concentrically lami- 
nated forms, two varieties of which are distinguished, the simple 
and complex. These correspond, in some respects, with the 
nodular calcifications described by Salter. These new-forma- 
tions of dentine, especiall} T if they are quite small, are liable to 
be confounded with simple calcifications. The latter, however, 
occur as discrete, roundish bodies in the parenchyma of the 
pulp, and never as confluent, very large grains, and, also, are 
met with, especially in the pulp of the root, in the form of 
needle-shaped, resistant bodies. A detailed description of them 
has been given, already, in connection with atrophies. 

Thin cross-sections of these new-formations present a central 
basis-substance, composed, in many cases at least, of transparent, 
discoid, homogeneous, structureless, nucleus-like masses, either 
single, in pairs, or in large numbers (Atlas, Fig. 5S), around 
which concentric layers are disposed in a manner similar to 
those around the Haversian canals in bone. The central sub- 
stance not infrequently contains globular masses and small in- 
terglobular spaces. If the basis-substance is unusually abundant, 
a very delicate, retiform, structure may sometimes be distin- 
guished with a high magnifying power and suitable light. By 

19 



290 NEW -FORMATIONS. 

means of very careful and slight corrosion, the concentru 
concentrically-disposed radiated layers are brought distinctly 
into view. Here and there, cloudy spots, together with m 
ular degeneration of the substance, presenting ;t gr;»y or dirty- 
yellowish color, are observed. 

The canals of the concentric dentinal new-forn 
centripetal course, i. e., they converge from the peripher 
the centre (Atlas, Fig. 0.5). As a rule, u r than in 

normal dentine, and, therefore, their diameters dimii 
rapidly; they deviate, frequently, from a din ranch 

without uniformity and often terminate in a tuft of tw._ 
branches. On account of the irregularity in which the? run. 
the intervals between them are variable: when the: Uilar 

masses present, they terminate at the centre in bular 

spaces. Anastomotic loops are met with, frequently, particularly 
in the complex forms. 

From the facts which have been Btated 
since the existence of dentinal canaU 

of dentinal cells, that the latter must have acquired a eir 
arrangement at the time of the formation of th< 
and that, as their proliferation pr 
from each other by larger intervals ai 
in the direction of their development 
^ Kot infrequently the canals are filled win 
like a string of pearls, or imbued with tl 
the blood, probably in consequence of extra) 
or of inflammatory processes in the Burrounding 
Erosions from resorption are obsen 
periphery of the new-formation which is Borro i 
atrophic pulp, and indicate a reaction on the pal 
vital pulp. There can be no doubt, therefore, ti 
formations are closely connected with morbid the 

persisting, though to be sure, in many cases, scanty n 
the pulp. 

Such a probability is strengthened by the anatomical exami- 
nation of these remains. Even though one portion of the pulp, 
which becomes reduced, frequently, to a thin membrane, hat 
quired a tendinous character or undergone a net-like 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 291 

another portion may still be traversed by well-preserved vessels 
containing fresh blood, and even bundles of nerve-fibres of 
normal appearance occur, which are still capable of transmitting 
sensations of pain. In many cases, it is true, these remains are 
totally obliterated. 

When the parietal, nodulated new-formations are organically 
united to the old dentine, a dividing layer is present, commonly, 
which usually has a light color and is perceptible to the naked 
eye, since the bounding layer of the old dentine is distinguished 
by the uniform appearance presented by the canals extending 
from it, while the canals of the new-formation meet those of the 
old dentine generally at an acute angle and. here and there, at 
nearly right angles: the latter rectangular diversion of the 
canals le most marked in many of the larger adherent new- 
formations (Atlas, Figs. 61 and 62). Globular masses with 
opaque interglobular spaces arc observed, here and there, in 
these transitional zones. In general, it may he stated that in 
secondary dentine following caries or abrasion of the teeth, the 
direction of the dentinal canals will be found to correspond 
with that of the canals of the old dentine, while in the parietal, 
concentrically laminated, nodulated new-formations, there is no 
correspondence in the direction of the respective canals. 

The periphery of the concentric new-formations usually pre- 
sents deep channels containing a varying number of bloodvessels 
(Atlas, Fig. 57), which, however, do not completely fill the 
cavities. Sometimes the coloring-matter of the blood is still 
perceptible and well preserved, and a corresponding reddish 
color of the dentinal canals, also, is observed ; generally, how- 
ever, the coloring-matter is changed to a dirty yellow, yellowish- 
brown, or to the different shades between this and a dark-brown. 
The wider channels are filled, more or less, with atrophic reti- 
form connective tissue in which the cavities of one or more blood- 
vessels with their sanguineous contents are perceptible. They 
vary in diameter, occasionally branch and, particularly in the 
complex forms, several even unite and form a sort of network. 
They frequently undergo calcification, in which cases the cal- 
careous particles in mutual contact compose the peripheral 
portion of their contents. Frequently they are surrounded by 



292 NEW -FORMATIONS. 

an accessory layer of varying thickness an<l with an indented 
surface towards the new-formation, in the folds of which 
lular body may, perhaps, be found, here and there, and I hare 
even met with well-formed, multiradiated, bone-corpuscl< 
them, so that it can be said that an osteoid 
around the bloodvessels. 

It may be assumed with reason, that the above-menti 
bloodvessels are derived from those of the pulp, c 
ously with a connective tissue which has a tenden ssifica- 

tion (Atlas, Fig. 59). 

These channels, which often are replete with calcareous salts 
and frequently contain bloodvessels, most not I inded 

with the usually smaller, hut occasionally m< 
irregular cavities which, as shown above, occur in the central 
portions of the new-formations, and in which the canal - 
quently terminate. I have met with a few ;' trur 

new-formations of osseous si(7>s<'>ut>-r within the parenchyi 
the pulp. They occurred in the pulps of mil! 
undergoing resorption, and one of th< in the 

above-cited communications by Heider ami Wedl. Upon the 
posterior surface of a milk incisor which wa* 
was a deeply-grooved breach of substance, about >ix millio 
in length, extending from the neck of the tooth toward* 
root, and the corresponding portion of the coronal and r 
pulp was denuded. The contents of the nerve-tubes «.f the 
latter had undergone a molecular degeneration, and the i 
tubes themselves presented in places a shrivelled appearance. 
Within the pulp, which was tinged with blood, a firm lamella 
was found united with the tissue of the pulp. :l l„.,it two milli- 
metres in length and one millimetre in breadth. Upon very 
close examination of the structure, it was found that tl 
more compact portion was ossified, while the marginal y 
was composed of aggregations of minute calca 
The lamella contained, as is the case, generally, 
osseous plates, several oval, sharply-cut foramina for the' I s 
mission of bloodvessels ; very distinct bone-corpusd s, 
were in clusters, were furnished with short processes ai 
the whole, bore a strong resemblance to thos 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 293 

mation. The new-formation of osseous substance, in this case, 
was due to the irritated condition of the pulp, engendered by 
its exposure. 

The greater portion of the very common osteo- dentinal for- 
mations is composed of dentine ; the bony substance occurs in 
very small quantity, and may consist merely of a group of a 
few bone-corpuscles. The osseous substance not infrequently 
attains only a rudimentary development ami resembles that 
which occurs upon the cement towards the neck of the tooth. 
It has been stated that bone-corpuscles sometimes make their 
appearance in the peripheral layer of the bloodvessels which 
have penetrated the new-formation ; they are also met with, 
however, either towards the periphery of the new-formation, 
where they occur in groups (Atlas, Fig. GO) and are separated 
from the new dentine by globular masses, or they occur in the 
central portion of the new-formation. Cases in which the cen- 
tral portion of the new-formation is occupied by an extensive 
mass of osseous substance are quite rare and, apparently, occur 
only when the formation acquires unusually large dimensions 
and presents a regularity in its development. In such cases, 
too, vascular canals are present in the bony tissue. A very fine 
illustration of a case of this kind is given in " WedTs Patho- 
logical Histology," Fig. 141 B, where the formation is attached 
to the wall of the dental canal of a bicuspid and is oval in shape, 
its long diameter measuring five millimetres ; it presents a pe- 
ripheral dentinal tissue, nearly a millimetre in thickness, which 
forms an annular investment to the central osteoid tissue. 

In these new-formations, both the bony and the dentinal tissues 
experience frequent interruptions in their development, as is in- 
dicated by the frequent occurrence of irregular, jagged cavities 
in the new dentine, and by the variable or dwarfish forms and 
the irregular disposition of the bone-corpuscles. 

Many of the parietal new-formations of dentine or osteo-den- 
tine, which are firmly adherent to the wall of the pulp-cavity or 
root-canal, displace more or less of the original dentine at the 
points of attachment, so that shallow depressions are perceptible 
upon the walls after the removal of the new-formations ; a par- 
tial resorption, therefore, must have taken place at these points. 



294 NEW -FORMATIONS. 

Not # infrequently, also, new-formations are intercalated in the 
original dentine and are then distinguished as interstitial. They 
are, commonly, multiple and, according to my experience, almost 
always occur in the roots of the molars. Fig. 66 in the Atlas 
illustrates such a formation, and Figs. 63 and '54. ah 
very good general view of them. They are met with, sometimes, 
in close proximity to the cement. Their structure always 
sents the same type, viz., their canals h.: tri petal c 

and open in central, larger or smaller, cavitii 
corpuscles, and in interglobular spaces when the; 
masses present. Not infrequently, ramifyii 
traverse the multiple formation and unite i 
Each of the formations has its own system <>f dentinal i 
which are invested by, and decussate freely with, 
the original dentine without, however, enteril 
munication with the latter. Just as in tl 

connection with hypertrophy of the an in- 

terstitial growth of bone, so, in the- present case, we 1. 
sume the occurrence of an 

The conditions of the occurrence of the latter remain unde- 
termined with our still defective knowledg 

of the teeth in general, and of the dentinal cells in particular; 
this much, however, is established, that resorption <>f t!. 
dentine is brought about by the interposition «»f the n 
is very probable, that the bloodvessels which, by tl., 
from the root-pulp, penetrate the dentine (Atlas^ 
and 98), have a definite connection with, and a: edium 

through which, on the one hand, the i n the 

other, the new-formation is accomplished. We I 
a canal containing a bloodvessel which may be tra 
origin in the root portion of the pulp. Accompany 
spheroidal, transparent, sharply-defined mae 
lobulated appearance from their mutual apposition, 
taming a minutely granular matter which pn 
tensive masses, a structure of radiated concentric laminae : 
are to be regarded as the rudiments of an osteoid - 
and all the more so from the fact that the vascular c I 
and then, are surrounded in places by globular n 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 295 

and at other times are found to be invested by an accessory, 
well-developed bony tissue with an indented, sharply defined 
margin directed towards the dentine. There occurs, then, an 
excentric development of the pulp-vessels and dentinal cells ; 
the new, more vigorous tissue displaces the old; the proliferating, 
fresh dentinal cells occupy the place of the dentine as the latter 
gradually undergoes resorption. 

On the other hand, isolated, either single or multiple, den- 
tinal and osteo-dentinal formations are met with in the substance 
of* the pulp, having a diameter of from one to several millime- 
tres, and a rounded, frequently lobulated form (Atlas, Figs. 57 
and 68). With regard to the development of these isolated, en- 
cysted new-formations, Heider and I, in the communications 
cited above, have maintained the view of the occurrence of an 
inversion of the layer of dentinal cells, and upon the following 
grounds: 1. The dentinal canals pursue a centripetal course : 
therefore, the dentinal cells, which enter into the formation of 
the latter and the development of which proceeds from the pe- 
riphery of the inverted portion (Einbuchtung) towards the centre, 
must have assumed an adequate arrangement ; 2. With multiple, 
encysted new-formations, we observed stelliform groups of den- 
tinal cells which we interpreted as the primary stage of the in- 
verting process (Insinuation) ; 3. An inversion of a group of 
dentinal cells and their detachment corresponds, also, to physio- 
logical processes, e. g., to the formation of the vesicles of the 
thyroid gland or ovarian follicles. Obviously, the inversion in- 
cludes, at first, a very minute space which becomes filled with 
new dentine; as the proliferation of the radiated groups of den- 
tinal cells progresses, new layers of dentine continue to be 
formed in the mass until the final separation occurs. The den- 
tinal cells upon the periphery of the new-formations do not ad- 
mit of direct identification, when the growth of the latter has 
ceased and they are invested by an atrophic tissue.* 

* R. H.ohl (iiber Neubildungen der Zahnpulpe und Deutsche Viertelj. f. 
Zahnheilkunde, 1868) does not accept this simple interpretation, and says, 
if this be the correct view, then we ought to find a sort of pedicle in every 
case, but he has never seen anything of the kind. New-formations are met 
with, however, indeed, they are by no means of rare occurrence, which are 



296 NEW -FORMATIONS. 

A netc '-formation of enamel cannot occur after the develop- 
ment of the enamel-cap is completed. Hence, in the combination 
illustrated in the Atlas, Fig. 69, it is not to be considered that 
the osteo-dentine and conical process of enamel, tog im- 

pose a new-formation; the pear-shaped, sharply defined cone of 
enamel, which encroaches upon one side of a truncated conical 
prolongation of the new-formation and is i:, . an annular 

layer of radiating dentinal canals, is the result of an anomaly 
in the development of an upper wisdom tooth, and an 
union has taken place between the new-format; lec- 

tin e and the dentinal layer which in mel. 

The combination with calcificationt^ ;lv in the smaller 

varieties of new-formations. i.< i 11( .. t W1 \ t } ie 

dentinal canals are very few in number, while the remainj 
portion presents concentrically disposed radiated lamii 
minutely reticulated, calcified mass and, consequently, I 
cretion or, in other words, the calcification of t! 
substance of the new dentine apparently predomil 
calcareous grains, as is the case in atrophic p 
46), are true concrements and occur, also, as ace 
in connection with hard new-formations, but never enl 
organic union with the original dentine: th< | within 

the parenchyma of the pulp and are calcil 
nective tissue. In general, it may | that all th< 

cesses which ensue in connection with atrophy. Bucfa I 
degeneration, obliterations, scl iccumulal 

masses within and outside of the vascular system 

also in pulps containing hard new-formati 



attached to the original dentine by means oi 
peases where there is no connection by. pedu 

With regard to thecharacter of the tissue within 
a decided opinion, namely, that it is new dentine. Hohl : 
to have recourse to a new formation of dentinal cells in the 
pulp-tissueand, with this idea, conceives that the pulp. - 
towards the centre, which participate in the new-format 

no w" U tr rl° rmati0n ° f * P» ] P into » dentinal c 

not .armon.ze with the views entertained at the prese, 

luteirT- h° the d0ntin °- "- ***** <* lls 

iThowevT dl8 1 hf ^ T m - with ^increa«n ? a S ,. 
tion, ho^er, which I am unable to confirm. 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 297 

Ulrich and J. Tomes called attention to the fact, which has 
been confirmed by many, that hard new-formations are of fre- 
quent occurrence in the much worn teeth of elderly persons, 
and that no distinction can be made as to their mure frequent 
occurrence in the incisors, canines, bicuspids, or molars. With 
many individuals there exists a predisposition (Diathesis) to the 
development of these new-formations, since they are found in 
several teeth in very great abundance. Finally, even the sound 
teeth of children are not exempt. The milk teeth, which enter 
upon a stage of senescence towards the period of dedentition, not 
infrequently contain hard formations in their pulps at the latter 
period of involution. 

These formations may be studied to great advantage in the 
teetli of mammals. The first histological investigations, under 
the head of ostco-dentine, are contained in the ki Odontography " 
of R. Owen. In the teeth of these animals, also, aside from 
other causative influences, the frequent occurrence of this for- 
mation is a phenomenon connected with the senescence of the 
tooth. Corresponding to the centre of the transversely abraded 
surface of a much worn lower incisor of a dog, I found a deposit 
of transparent secondary dentine, measuring one-half a millime- 
tre in depth, and with its canals extending in conformity to those 
of the original dentine. In several worn front teeth of the 
lower jaw of a common hedge-hog (Erinaceus Europ.), I have 
met with multiple osteo-dentinal formations attached to the wall 
of the root-canal. These were of an ellipsoidal or cylindriform 
shape, their long diameters measuring, in some cases, one mil- 
limetre; elongated vascular canals traversed a few of the larger 
ones; their central substance was occupied by bone-corpuscles,, 
and their peripheral portions were traversed by an abundance 
of centripetal dentinal canals. In a molar from a horse, the 
coronal surface of which was much worn away and hollowed out 
in the form of a channel, and the root of which was notably 
contracted upon either side, had become atrophied, several con- 
centrically laminated new-formations, which were united to the 
dentine, were found in the single, considerably narrowed canal. 
In the atrophic roots, near their junction towards the neck of 



298 NEW-FORMATIONS. 

a molar from an ox, I met with very finely developed, vascular- 
ized, multiple, interstitial, dentinal new-formations. 

It is not an uncommon occurrence to find, in the ivory from 
the hippopotamus, spherical or cylindrical deposits (interstitial 
new-formations), which are removed by the dental artificers as 
unserviceable; they are composed of remarkably fine concen- 
tric layers of dentine, in which the canals of the different laminae 
pursue a centripetal, undulatory course, at uniform intervals from 
each other. The new-formations are connected with the ivory 
by means of a transparent, intermediate layer which does not 
possess the structure of dentine, but presents a structureless, mi- 
nutely granular basis-substance, with sharply defined, lobulated 
borders towards the dentinal layers. Sometimes, quite distinct 
bone-corpuscles may be recognized in this connective zone, jind, 
therefore, there can be no doubt but that we have presented in 
it an osteoid substance, in which extend numerous vascular 
canals with occasional sac-like dilatations. 

The stalactitic forms, which occur upon the wall of the pulp- 
cavity of elephants' tusks, Avere recognized by A. Haller. R. 
Owen states that they are, obviously, the result of circumscribed 
inflammation or malformation of the pulp. In the root-portion 
of tusks, I have observed very numerous hard new-formations 
projecting into the pulp-cavity and presenting a great variety 
of forms, as conical, dentiform, nodular, lamellar. &c. The very 
thin lamellar forms are composed, principally, of bony tissue, 
while the dentiform or superficially smooth, nodular, thicker 
forms consist of bone, together with dentine in its various transi- 
tional stages, or principally of the latter. 

It is not uncommon to meet with very imperfect ivory in the 
root-portion of the tusk ; for instance, osseous tissue may be im- 
bedded in it in a very irregular manner and to a considerable 
extent, or the dentine is traversed by numerous vascular canals, 
at tolerably uniform intervals, or spherical, encapsulated, new- 
formations of dentinal substance are interposed: in consequence 
of the presence of these, the surface of a cross-section presents 
confluent or discrete yellowish grains, interspersed with lighter 
masses; the grains vary in size from that of the head of a pin 
to that of a pea, and may even be larger. These faulty formations 



NEW- FORMATIONS OF HARD TISSUES OF TEETH. 299 

sometimes extend into the projecting coronal portion and are well 
known to the ivory turners, since the ivory containing them is un- 
suitable for very delicate work on account of its diminished hard- 
ness and elasticity, nor is it capable of receiving so fine a polish. 
In a technical point of view, therefore, they are of importance. 

In regard to the question whether these hard formations in 
the pulp have a physiological or a pathological signification, it 
must, first of all, be borne in mind how difficult a matter it is, 
as a rule, to distinguish between a physiological and a pathologi- 
cal phenomenon, and this is all the more the case in the present 
instance where we have to do with senile changes in an organ, 
in the majority of cases. Hence, it must be admitted that the 
answer cannot be given with absolute precision. Where do the 
senile phenomena end and the pathological begin? The fact 
that the hard new-formations occur in quite old teeth, present- 
ing abraded coronal surfaces without any further evidences of 
disease, and that they are of frequent occurrence in the older 
teeth of animals, indicate, to a certain degree, that we are not 
to lay very much stress upon the pathological element; on the 
other hand, special conditions appear to be necessary for their 
development, from the fact that they are not found in all senile 
teeth. They are to be considered as the results of an inde- 
pendent process, which is based upon a hyperplastic, local- 
ized development of dentine, which process is unaccompanied by 
pain; it is to be observed, however, that pulps containing den- 
tinal new-formations do not lose their susceptibility to painful 
impressions, since the nerves in the vicinity of the new-forma- 
tions may be well preserved and capable of conduction ; it is 
quite possible, also, that, under special conditions, in teeth on 
which the dentinal covering has been very much worn away 
they may occasion a painful sensation in consequence of a me- 
chanical injury and that, as their growth continues, they may 
give rise to derangements in the circulation and even to in- 
flammatory processes in the remaining portions of the pulp, and 
to consecutive periosteal inflammation. 

E. Miihlreiter* considers the new-formations of dentine and 

* Deutsche Viertelj. f Zuhnheilkunde, 1868. 



300 NEW -FORMATIONS. 

t<he calcifications to be independent processes, which of them- 
selves give no indications of their occurrence and are unaccom- 
panied by painful sensations. "When these processes are asso- 
ciated with other pathological changes, especially with those of 
an inflammatory nature in the pulp-tissue which is not implicated 
in the development of the new-formation, then they acquire a 
clinical interest from their influence upon the course of the 
morbid process. According to McQuillen,* new-formations of 
dentine in the pulps of teeth, not affected with caries, sometimes 
give rise to the most intense neuralgias which, not infrequently, 
are referred to other teeth and considered to be the result of 
sympathetic irritation. A continuous, boring, pain which is 
felt invariably at one and the same spot, he remarks, is a quite 
positive indication of the presence of a new-formation. If this 
be the case, consecutive periodontitis ensues. In a case reported 
by Tanzer,f there was unremitting pain referred to the last tooth 
in the lower jaw; this was removed and the pain returned in the 
next tooth in front; in consequence of the repeated migration 
of the pain to the adjacent tooth, one tooth after another was 
extracted, as far as the lateral incisor, during a period of eight 
to nine years. Each of the teeth extracted presented well- 
marked examples of unattached and parietal new-formations, 
and, in the opinion of Tanzer, this man, who was then thirty- 
four years of age, probably will not obtain release from his 
suffering until all the teeth have been removed. 

The new-formations also derive importance in connection with 
the operation of filling, and HulraeJ expresses his ideas upon 
this point in the following manner: "There can be no question, 
if it is possible to preserve the pulp of a tooth and then stop it, 
that such a tooth is in a far more healthy condition than where 
the interior of the crown and the fang is" filled with gold or anv 
foreign material. I am fully convinced that many of the teeth 
which of late years have been treated by destroying the pulp 
might, under another mode of treatment* have been preserved 
without sacrificing this essential portion of the organ. So long 

* Dental Cosmos, ]868. 

f Deutsche Viertelj. f. Zahnh.. 1869. 

t Dental Review, 1801. 



MUSKET-BALLS IN THE TEETH OF ELEPHANTS. 301 

as there is a layer of dentine existing over the pulp, as a general 
rule, it should never be removed, even if the dentine is softened 
nearty to the surface of the pulp." 

MUSKET-BALLS IN THE TEETH OF ELEPHANTS. — Elephant-- 
hunters very frequently employ firearms and take aim at the 
eye, ear, and mouth, so that it will readily be seen that the 
balls, instead of penetrating through the skull into the base of 
the brain, may enter one or another tooth and give rise to pro- 
cesses in the dentine and the wall of the pulp- cavities, which 
acquire a great pathological interest. Goethe, long ago (1798), 
investigated the subject of diseased ivory from the elephant's 
tusk resulting from the impaction of iron or leaden balls ; the 
process appeared to him to be a sort of coagulation (Gerinnung) ; 
he also mentions the occurrence of exostosis upon the wall of 
the pulp-cavity in cases where a ball entered the posterior, weak, 
and hollow portion of the tooth. Cuvier, also, recognized the 
irregularity in the dental mass around the balls. R. Owen was 
the first to call attention to the change produced in the histo- 
logical structure, and says that musket-balls and other foreign 
bodies which become imbedded in ivory become surrounded by 
osteo-dentine, in greater or less amount. If the ball penetrates 
the root portion and enters the pulp, the track made in the pas- 
sage of the former becomes filled by a thick deposit of cement 
from without ;md of osteo-dentine from within. 

By the kindness of Prof, von Schroff, I had the opportunity 
of examining five specimens from elephants' tusks in which iron 
balls were imbedded, from the pharmacological collection. The 
malformed dentine, which is recognizable by the naked eye, is 
shown very distinctly in cross-sections ; it has, generally, a 
dirty-yellow color, is tolerably well defined towards the sound 
dentine, its general outline, as well as its extent, being variable. 
The tissue is wanting in uniformity and presents an abundance 
of interlacing wavy striated markings. This faulty formation, 
however, is not confined to the immediate vicinity of the im- 
pacted ball, but is found, also, at various distances from it in the 
form of isolated, concentrically-striated patches. The reaction 
which is induced by the presence of the foreign body sometimes 
leads to the formation of an abscess in the dentine (comp. p. 188). 



302 



NEW-FORMATIONS. 



The faulty formation may be traced along the track mad 
the ball (Fig. 86). A depression, corresponding in size with that 



Fig. B6. 




of the ball, together with several Bmooth I 
as the head of a pin (new-formatioi 

terior of the tooth, especially in ca*ea where the ball ti- 
trated in a direction transverse to the 1 

If the ball traverses the pulp-cavity in a transvi 
crushing the pulp in its passage, thei 
osteo-dentine which, in the case illustrated, 1. 
pearance upon the surface presented in the pulp- cavity 
consists of pyramidal tubercles and nodal 
color. Thin transverse sections of the latter present abundant 
globular substance and entangled, confused n 
canals and, in other places, multiradiated I" 

these new-formations especial inter* irded by 



* Fig. 86 shows a section taken from an elephant's n the 

left side the segments of two iron bullets which h»\ 
dental pulp and become fixed, partly to the wall of the pulp- 
partly to the contiguous dentinal tissue. The . the bullets 

entered is seen at (a) ; in a transverse direction from t 1 
the track traversed by them, which is indicated by an irregular, 
course of the striae. The dentine, both in the vicinity o( the latter hi 
of the transversely-divided bullets, is transformed in: 

is quite sharply defined, displays wavy strhe and. for tie- I .. • ■ dirty- 

yellowish color. The hard formation, which form- 
across the pulp-cavity, presents in cross-section an irregular, multipl 
centrically-laminated osteo-dentine. In the vicinity of tl • ullet a 

circumscribed suppuration occurred. Two-third.- natural 




MUSKET-BALLS IN THE TEETH OF ELEPHANTS. 303 

defined, interposed dentinal portions, from one to several milli- 
metres in thickness, which have a rectilinear, angular configura- 
tion, present the texture of the normal dentine and are encap- 
sulated by a thin layer of osseous tissue. Evidently, they are 
spicula of ivory which became impacted in the pulp and gave 
rise to a proliferation of bone-corpuscles by means of which 
they became invested by osseous tissue in the form of a sheath. 
The osteo-dentinal formation, then, succeeded the latter. 

In cases where the ball penetrates 

to the wall of the pulp-cavity and ' 

the corresponding portion of the wall 
becomes implicated in the faulty 
formation of the dentine (Fig. 87) a 
proportionately large osteo-dentinal 
mass, with jagged and warty excres- 
cences, is found projecting into the 
pulp-cavity. 

The pulp- wall may, however, be 
protruded, merely, by the ball and remain smooth (Fig. 88). 
Osteo-dentinal formations, which first make their appearance 
at some distance from the locality of the ball, may owe their 
origin to displaced dentinal fragments, or a local concussion, 
merely, may be sufficient to occasion their development. 

As ivory admits of a certain amount of expansion, in conse- 
quence of its elasticity, and. moreover, since the shattered por- 
tions become filled with a reparative tissue, the point of entrance 
of the ball upon the exterior of the tooth may easily escape ob- 
servation, and the ivory turner is first made aware of the pres- 
ence of a ball when he attempts to saw through the tusk. 

The molars from elephants are employed less frequently in 

* Fig. 87 shows a segment from the tusk of an elephant, containing small 
fragments of an iron ball in the wall of the pulp-cavity. From the appear- 
ance of the surface of the section presented in the figure, it is seen that an 
abnormal tissue, with a sharply defined outline towards the normal dentine, 
is disposed upon the periphery of the ball, forming a capsule for a certain 
portion of the latter, and represents the basal portion of a new-formation 
which, upon the opposite surface of the preparation, projects into the pulp- 
cavity in the form of notched and warty, superficially smooth osteo-dentine. 
Natural size. 



304 



NEW-FORMATIONS. 



the arts and, therefore, there is rarely an opportunity to obtain 
sections of them ; the teeth, moreover, being inclosed within 
the mouth, are less liable to be penetrated by balls. A case in 
point, however, is illustrated in Fig. 89, where, in a molar, an 
osteo-dentinal mass, inclosing a flattened, leaden ball, is inter- 
posed between the folds of the enamel, on the other side in the 
substance of the dentine and is in relation with the cement. 



Fig. 88.* 





New-formation of Osseous Substance in Connection 
with Abscesses in the Ivory of the Tusks of Elephants. 
— The reparative tissue which is formed upon the wall of an 



* Fig. 88.— Segment from the tusk of an elephant, containing an iron ball 
which has penetrated as far as the pulp-cavity and has formed a bulging 
protuberance upon its wall which has given rise to several, superficially 
smooth, warty new-formations with broad bases, partially visible at (a) in the 
oblique view of the preparation. In the immediate vicinity of the ball, the 
cavities of small abscesses and, also, osteo-dentine, are perceptible. Two- 
thirds natural size. 

f Fig. 89 shows a portion of a transverse section of the molar from an 
Elephas Indicus from Ceylon, containing the flattened segment of a leaden 
ball. (For the use of this specimen the author is indebted to Prof. D. L. 
Schmarda.) If the three dental substances be traced out, it will be seen that 
the enamel (a, a), at a certain distance from the fragment of the ball, and 
also the dentine {b, b), have been displaced by a substance (c, <*), which forms 
an investment of varying thickness around the fragment of the ball and, 
when traced farther, is found to enter into immediate connection with the 
cement. Hence the new-formation was developed by a proliferation into 
the enamel and dentine. Natural size. 



NEW-FORMATION OF BONE WITH ABSCESS IN IVORY. 305 

abscess in ivory, is osseous substance, as has been shown before 
(compare Inflammations, p. 188). The very marked prolifera- 
tion of the osseous tissue encroaches upon and induces a resorp- 
tion of the ivory at the corresponding parts ; the contour of the 
interstitial new- formation, therefore, is not clearly defined. 
The zone of proliferating osseous tissue varies in its extent be- 
tween several square millimetres and, perhaps, a square cen- 
timetre, and presents a marbled appearance. (Fig. 90.) The 

Fig. 90.* 




brighter, more transparent portions correspond to the osseous 
substance, the less transparent, insulated portions, hemmed in 



* Fig. 90 shows an osseous new-formation from the wall of the cavity of 
an abscess in the tusk of an elephant. (The specimen was taken from the 
portion of the segment indicated by a, in Fig. 75.) From the internal sur- 
face (a) of the cavity of the abscess as far as (e), where the normal dentine 
commences, the dentine is displaced by an abundantly vascularized osseous 
layer. The bloodvessels are transversely divided, for the most part, and are 
surrounded by a luminous ring. The opaque, dotted portions (b) corres- 
pond with the localities where granular cloudiness is visible, and, here and 
there, the remains of the ivory may still be recognized. The brighter spots 
contain, for the most part, bone-corpuscles which appear in the figure in the 
form of puncta ; in many places, e. g., near the middle portion (indicated 
by transverse lines), the bone-corpuscles are wanting, and in place of 
them is seen merely a diffused, granular mass. At the zone of transition 
into normal dentine (c), quite bright spots are perceptible upon the right side, 
which are suggestive of clustered globular masses ; upon the left are the open- 
ings of transversely and obliquely divided bloodvessels, which are surrounded 
by a luminous ring and are imbedded within the dentinal substance. Mag- 
nified five diameters. 

20 



306 NEW -FORMATIONS. 

by the latter, correspond to the dentine which has undergone 
re'sorption. 

The osseous substance in the vicinity of the cavity of the 
abscess presents all the characteristics of a young bony tissue ; 
the osteoblasts inclose a nucleus together with prominent 
nucleoli, and present a variety of forms resulting from division ; 
their canaliculi are met with, chiefly, in the form of short, den- 
tated prolongations from the body of the cell ; several osteo- 
blasts, also, are inclosed within a common cavity with an indented 
outline. In the deeper layers of the new-formation which sur- 
rounds the cavity of the abscess, young, osseous substance 
occurs, particularly in the neighborhood of the vascular canals, 
which latter are invested, as with a sheath, by a light substance 
composed, in part, of minute globules and, in part, of con- 
centric layers with radiated markings. It is hardly necessary 
to add that the latter corresponds to an osteoid formation. 
Numerous vascular canals are prolonged into the ivory, ad- 
vanced guards, as it were, which serve as the medium through 
which the resorption of the ivory and the formation of bony sub- 
stance are effected; I have been unable to ascertain their origin, 
as only segments of tusks were at my disposal. 

I endeavored to identify, in the dried mass which lines the 
cavity of an abscess, a vascularized connective tissue from which 
the bloodvessels, that are prolonged towards the ivory, may pos- 
sibly have originated, but was unable to come to any satisfactory 
conclusion, in consequence of the marked degeneration of the 
mass. 

The resorption of the ivory is presented in various stages, as 
has been referred to before (compare Inflammations, p. 189). 
The first indications are afforded by the appearance of numerous 
minute cavities, with indented margins, which resemble inter- 
globular spaces and gradually render the dentinal canals less 
recognizable, so that, finally, there remains only a substance re- 
sembling minute globular masses, the limits of which are gradu- 
ally contracted by the encroachment of the osseous substance. 
Yv r e find, then, that in the vicinity of these chronic abscesses. 
also, a more vigorous reparative tissue is developed in the place 
of the less vigorous; in other words, an interstitial growth of 



FRACTURED TEETH. 307 

osseous substance ensues in the vicinity of the cavity of the 
abscess. 

Fractured Teeth. — Since fractures of the teeth, produced 
by blows, thrusts, falls and awkward attempts at extraction, 
cannot be regarded as uncommon occurrences, it might be ex- 
pected that among a very large number of teeth an instance of 
a reunited fracture would be met with now and then. But we 
may examine thousands of teeth which have been extracted 
during life or removed after death without meeting with a single 
case of a reunited fracture. Formerly, therefore, the occurrence 
of the latter was doubted, but the accurate observations of 
modern times have settled the matter beyond cavil. Hohl 
recently* collected all the known cases of reunited fractures, 
fourteen in number, including two cases observed by himself. 
Three cases occurred in the teeth of the hippopotamus, two in 
those of the horse, one in the tooth of an antelope, seven in human 
incisors, and one in an upper bicuspid. If we add the case of 
Rogers, mentioned by Tomes,f in which an upper molar was broken 
off transversely at the neck, there will be fifteen cases in all. 

When we consider the great frequency of conflicts among ani- 
mals, it will readily be understood that the canines of the larger 
mammals, which are employed as weapons for giving blows, pre- 
sent a large, unprotected surface and are exposed to manifold 
external influences, are quite liable to meet with severe mechani- 
cal injuries, and it is probable that more careful observations 
will show that with these animals, fractures of the teeth are not 
such rare occurrences as has been supposed. 

Reunited, comminuted fractures afford evidence of the remark- 
able increase in the vital activity which may be manifested in a 
tooth. J. TomesJ mentions an instance of a severely com- 
minuted fracture of the tusk of a hippopotamus, within the 
socket and with considerable displacement and quite wide sepa- 
ration of the fractured portions. In this case, union took place, 
and was effected by the development of cement. In a case of 
reunited fracture of the lower canine of a hippopotamus, de- 

* Deutsche Viertelj.f. Zahnheilk., 1870. 

f 4 System of Dental Surgery. J System of Dental Surgery. 



308 NEW -FORMATIONS. 

scribed by Owen,* the reparative tissue was composed of osteo- 
dentin, and this may, possibly, be the case in all instances where 
the pulp participates in the reparative process. 

Two cases of united fracture, one of a human upper bicuspid 
and the other of a lower incisor of an antelope, which were re- 
ported by myself, f and are illustrated in the Atlas, Figs. 73-78, 
inclusive, afford a very clear idea of the character of the repara- 
tive tissue. 

In both cases, which are distinct from each other, there is 
presented a completed reparative process which originated in the 
root-pulp in the first case, where the fracture was through the 
root of the tooth, and in the coronal pulp in the second case, 
where the fracture occurred in the crown. In both, a firm re- 
parative tissue was developed, consisting essentially of three dif- 
ferent substances, namely, dentine, globular masses, and bone. 
In the first case, it formed a firm cement by means of which the 
union of the two fractured ends was effected, and in the other, a 
protective covering for the body of the pulp. In the latter case, 
then, it was more like a cicatrization of the pulp. 

In the first case, the regeneration of hard tissues was effected, 
principally, from the root-pulp, and only to a limited degree from 
the periosteum of the root. The systems of dentinal canals, 
which are interposed in the substance of the callus, must have 
originated from a proliferation of the dentinal cells between the 
fractured ends. The new-formed osseous substance, which is 
disposed upon the fractured portions of the dentine, is, likewise, 
a product of the root-pulp, the production of osseous substance 
from the latter being possible, as we know; the cement-layers 
corresponding with the fracture, are not thickened and, there- 
fore, the periosteum of the root, the medium through which the 
nourishment and growth of the cement is effected, has furnished 
merely a cementing substance upon the periphery of the frac- 
ture. The proliferation of the osseous substance between the 
fractured surfaces of the dentine is prolonged for some distance 
into the substance of the latter, so that the fractured portions 
are intimately united. 



* Odontography. + Deutsche Yiertelj. f. Zabnheilk., 1*67. 



TRANSVERSELY OR OBLIQUELY FRACTURED ROOTS. 309 

In the second case, in which the outer segment of the crown 
was broken off, an osteo-dentinal mass was developed from the 
body of the pulp outwards, and presented the following appear- 
ances. The proliferated, abundantly vascularized, dentinal sub- 
stance was covered over with bone which, likewise, was traversed 
by numerous vascular canals, an arrangement similar to that 
presented in the first case. It is very common, indeed, to ob- 
serve that a new-formation of dentine is accompanied by that 
of bloodvessels, which latter, however, gradually become oblit- 
erated and undergo calcification. In consequence of a defect 
in the wall of the pulp-cavity, it was possible for the proliferating 
hard tissue to project beyond the edge of the fracture, and the 
surface beyond the new dentine became the seat of an ossifica- 
tion process. 

A concurrence of favorable circumstances is requisite in order 
to insure the complete union of a transverse or oblique fracture of 
the root of a tooth. First of all, it is necessary that the frac- 
ture should be simple, as nearly as possible, and without any 
aggravating complication. If the pulp is subjected to great 
traction, is crushed or lacerated, its suppuration or gangrene 
will be all the more likely to occur and to interfere with the 
reparative process and occasion the death of both the fractured 
portions. If, on the other hand, a large portion of the periosteum 
of the root is injured, a consecutive inflammation will furnish an 
insurmountable obstacle to the process of repair. The connec- 
tion of the tooth with its socket must not be so far broken that 
the fixation of the former in the latter is impossible. A repair 
also requires a healthy, vigorous condition of the individual, and 
a proper care of the fractured parts after they have been ap- 
proximated. Absence of these favorable conditions and neglect 
of proper precautions are to be regarded as the probable causes 
of the comparative infrequency of reunited fractures of the roots 
of teeth, which the dentist is called upon to extract in conse- 
quence of the intense pain which the patient experiences from 
them. 

In a case observed by Saunders,* the fracture extended ob- 

* J. Tomes' Lectures on Dental Physiology and Surgery. 



310 NEW- FORMATIONS. 

liquely through the middle of the root of a human incisor; per- 
fect union took place with slight displacement. In a case which 
occurred in the practice of J. Tomes,* a front tooth of a patient 
under twenty years of age, was fractured transversely by a severe 
fall. After the lapse of some time the patient determined to 
submit to no further inconvenience, and the tooth was extracted. 
The tooth had been broken transversely, some distance within 
the socket, and the fractured surface had been coated over sub- 
sequently with cementum. Had the tooth, continues Tomes, 
been kept for a time by any mechanical means in a state of rest, 
it is probable that a union of the fractured surfaces would have 
been effected. f A case of reunited fracture of an incisor is con- 
tained in the Breslau Anatomical Museum. J The root of a 
student's incisor was broken across with a fencing foil, in the 
gymnasium. The fragment was found to be still attached to 
the gum, and was pressed back into the socket by the surgeon in 
attendance. It regained its original firmness, but there ensued 
such intense pain that it afterwards became necessary to remove 
the tooth, which presented a slight lateral displacement of its 
consolidated fragments; the nerves were found to be bent from 
their course at the corresponding part, and this condition, to- 
gether with the compression to which they were subjected by 
the encircling callus, gave rise to the odontalgia. In a case of 
a perfectly united fracture of an upper bicuspid, in Heider's 
collection, there is scarcely any displacement of the fractured 
surfaces which are separated by an interval of only 0.7 of a 
millimetre, the latter being occupied by newly-formed compact 
tissue, which unites the two surfaces. Hohl§ refers to the fol- 
lowing case : " A boy, thirteen years of age, fell from the roof of a 
house and fractured the right upper central incisor in such a way 
that its crown could be moved backwards and forwards, and it 



* System of Dental Surgery. 

f The author has neglected to insert an important portion of Tomes" de- 
scription of this case, in which " a front tooth was broken across and a molar 
tooth loosened by the fall. The latter tooth was allowed to remain, on the 
chance of its regaining its original firmness of implantation. After the 
lapse, &c.' r — Trs. 

1 Hyrtl, Topograph. Anatomie, Bd. I. g Op. cit. 



LONGITUDINAL FRACTURE OF CROWN AND ROOT. 311 

was feared that the tooth would drop out. However, it became 
firmer from day to day, and in a few weeks it regained its nor- 
mal firmness. I saw the boy about a year after the occurrence 
of the fracture. The tooth differed from the rest of the teeth 
present in the mouth, neither in respect to color or degree of 
firmness. The crown presented two small defects in the enamel. 
Upon the labial surface of the alveolus of the tooth in question, 
a slight bulging could be felt quite distinctly, about fifteen mil- 
limetres from the edge, and this, evidently, was the locality of the 
fracture." 

Longitudinal fractures of the crown and root, also, may become 
perfectly united, and even the enamel in the fractured portion 
may become united by cement tissue. Hohl reported the fol- 
lowing case: "Prof. V. , as he was about entering a railway car, 
on his way to take charge of a hospital in Bohemia, in the year 
1866, fell, striking his mouth upon the sharp edge of an iron step 
in such a way that the upper large incisor on the right side was 
broken lengthwise. The fracture separated the tooth in the 
middle of the crown so completely, that the two fragments di- 
verged from each other and could be moved back and forth. 
After the lapse of fourteen days, during which time intense pain 
entirely prevented the use of the fractured tooth, a more com- 
fortable condition ensued, and in a few weeks more the tooth 
completely resumed its normal functions. At the present time, 
the two halves of the tooth are firmly adherent to one another, 
and the direction of the fracture is indicated merely by a fine 
line, with a slightly brownish tinge. As the line is perpendicu- 
lar to the transverse axis of the tooth, it is to be presumed that 
the fracture also involved the root." To this category, also, 
probably belong the united fractures of two molars of a horse, 
contained in the Museum of Berne, with regard to which Valen- 
tin* states that the fissures of both the enamel and true dentine, 
which were produced by the original injury, are closed by true 
bony tissue. 

Transverse and oblique fractures of the crown, in which the 
pulp is wholly or partially exposed, lead in rare cases to a re- 

* Wagner's Handworterbuch der Physiologie, Bd. I. 



312 NEW- FORMATIONS. 

raarkable cicatrizing process on the part of the pulp. J. Tomes* 
reports a case in point from Arnold Rogers. A patient applied 
to have the roots of a first molar removed, the crown of which 
had been broken off, previously, when attempts were made to 
extract it for the relief of intense pain consequent upon car 
After the lapse of several months, the remains of the broken 
tooth occasioned annoyance and, therefore, were remow 1. I: 
was found that secondary dentine had been formed, which not 
only projected from the cavity but, also, overlapped and con- 
cealed the sharp edges produced by the fracture. We have met 
with a case quite similar to the latter, in an oblique fracture of 
the crown of a tooth of an antelope. 

The diagnosis of a fracture of the root, now and then, may 
be attended with difficulty, and Ilohl refers particularly to the 
danger of confounding such a case with a luxat: q. Extri 
teeth which present irregularities of formation in the form of 
bent or twisted crowns or bent mp. p. 1 v be 

misinterpreted as cases of fracture, if sufficient care be not ex- 
ercised in ascertaining the true condition. 

Cement — Osteomata — Exostoses. — Although th< i 
sentially, localized hypertrophies, it is justifiable, hi rom 

a clinical point of view, to consider them separately 
are, sometimes, the cause of very severe pain and i neu- 

roses in remote parts, which is not the lually, with ordi- 

nary hypertrophies. 

Osteomata are distinguished as single and multiph . 
and confluent. The solitary osteomata generally have the f< 
of tuberous excrescences (Knotchen), with broad basal port: 
and, usually, occur in the vicinity of the apex of th< 
erally they have a diameter of a few millimetres, and a ronn 
convex outer surface which, in most c narked with mi- 

nute elevations and depressions. They rarely attain such di- 
mensions as were presented in the case of a canine tooth illus- 
trated by J. F. Meckel, f where the osteoma originated at the 
neck and invested the entire root; the thickest portion 
upon the facial side ; the surface was smooth in some plac -. 



System of Dental Surgery. f Tabula? anal III. 



. CEMENT — OSTEOMATA — EXOSTOSES. 313 

•while in others, it was marked with several pits. According to 
the illustration, the thickest portion of the tumor measured 2.7 
centimetres. The knotty, discrete osteomata occur in groups 
of two or three, at slight intervals from each other, or are 
massed together so as to present a warty appearance (Atlas, 
Fig. 108). Numbers of delicate spinous and lamellar excres- 
cences, which are to be distinguished from appearances result- 
ing from resorption and, sometimes, spread over the entire 
periphery of the root, impart a rough character to the outer 
surface of the cement. The bicuspids and molars, more fre- 
quently than other teeth, present this condition, and sometimes, 
merely one surface of the root is the seat of a large osteoma, 
while the remaining roots or surfaces of a root are entirely 
free. 

Histologically, they consist of circumscribed superpositions of 
new layers of osseous substance, which are developed, one over 
another, in the form of a dome, with the base resting upon the 
original cement (Atlas, Fig. 107) ; they form irregular undula- 
tions beyond the level of the cement, and compose the sole ele- 
ments of the pyramidal excrescence, the outer surface of which, 
generally, is covered with tuberculated prominences. Their sub- 
stance is rendered cloudy, always, by the presence of less trans- 
parent and even opaque layers, and to this condition is to be 
referred the fact that, when viewed with the naked eye, the os- 
teomata appear brighter and whiter in comparison with the nor- 
mal cement. 

In respect of size, form, disposition, and number, the bone- 
corpuscles present a great variety. The remarkably uniform 
laminae, which are readily brought into view after the extraction 
of the calcareous salts by means of dilute hydrochloric acid, are 
disposed in a concentric manner, present radiated markings and 
are most conspicuous where the basis-substance occurs in greatest 
abundance and the bone-corpuscles, consequently, are separated 
by the widest intervals. The radiating, striated markings can- 
not possibly be occasioned by the bone-canaliculi ; indeed, even 
with the use of very high magnifying powers, there are places 
which do not contain a single canaliculus ; but reasoning from 
the analogy between them and the appearances presented by the 



314 NEW- FORMATIONS. 

concentric radiations of concretions, e. g., of carbonate of lime 
in the urine of herbivorous animals, especially of the horse, and 
in renal cysts, or of uric acid in vesical calculi, it seems to me 
in the highest degree probable that they are produced rather by 
a radial disposition of needle crystals of calcareous salts in the 
layers of the basis-substance. In another view, this arrangement 
also occasions a minutely-granular marking, which, sometii 
assumes a yellowish or yellow-brownish color from the de] 
of pigment. 

Young, interstitial bone-corpuscles, clustered together and 
surrounded by a capsule, are met with, sometimes, in the 
ripheral zones, and are crowded, as it were, in to .the elder la\ 
The latter undergo a necrobiosis in pi; 

parent bone-corpuscles lie in the dirty yellow, yellow-brown' 
brownish-black basis-substance which has undergone a irrannlar 
metamorphosis. Those bone-canaliculi. which lire elongated, 
tend in parallel rows and, in this respect, ai den- 

tine, become the seat of accumulations of an ilar 

mass, in consequence of which they frequently present a m 
voluminous appearance. The necrobi tnonly occurs in 

circumscribed spots, and is associated with the freqoentlj- oblit- 
erated vascular canals which for the most part are of Bmall 
calibre and quite few in number as a general rule. I have not 
met with any case in which ramifications of the latter * 
be seen. 

If a decalcified section be boiled in very dilute hydrochloric 
acid until it acquires a pultaceous consistence, or nearly 1: 
the sharply-defined osteoblasts with their Bhort , 
brought into view, either isolated, in consequence of the lie 
faction of the basis-substance, or still imbedded in the la; 
which becomes remarkably clear. The more delicate ramifica- 
tions of the bone-canaliculi succumb immediately to the liquefy, 
action of the acid, while the elongated, thicker ones, which 
towards the periphery, resist the action much longer and mav 
be traced to a considerable distance: in the vieinftv of the 
ripheral portions of the new-formation, isolated rith 

thick, frequently varicous processes are met with, which, prob- 



CEMENT — OSTEOMATA — EXOSTOSES. 315 

ably, belong to the derivative forms. The younger the osteo- 
blasts, the more readily may they be isolated. 

The cement osteomata are developed slowly, give rise, fre- 
quently, to intense, piercing, gnawing, lancinating pains, and 
may even occasion prosopalgia (comp. Neuroses). A case came 
under the observation of J. L. Levison,* where death ensued 
from an exostosis of the root, which gave rise to an affection of 
the membranes of the brain. The marked painfulness is due to 
the increased tension of the nerves of the periosteum of the root, 
and to the secondary affection of the branches of the nerves of 
the pulp. The location of the exostoses, at the apex of the root, 
renders the latter all the more liable to occur. Whether or not 
the existence of gout favors their development is still unde- 
termined. 

Quite extensive bony excrescences upon the cement also occur 
as anomalies of development, and the two following are to be 
regarded as cases in point. Forget, in his anomalies of the 
teeth, cites a case, communicated to himself by Maisonneuve, 
where a carious lower molar presented a tumor as large as a 
pigeon's egg, which was attached to the root, rather upon the 
lateral surface, by means of a pedicle, and was composed entirely 
of osseous substance. A longitudinal section displayed a line of 
demarcation between the tumor and the root. The connection 
of the two was so intimate that in the preliminary extraction of 
the tooth for the purpose of facilitating the examination and 
separation of the encysted mass, the latter, also, was removed. 
Letenneurf met with a tumor in the lower jaw of a woman, 
thirty-four years of age. When extirpated, it presented an 
irregular form and was three and a half centimetres in length 
and two and a half in breadth ; the adjacent bicuspid was com- 
pletely developed, of a white color, and attached by its apex to 
one side of the tumor. The latter presented a gray color, the 
hardness of ivory, and resulted from an hyperplasia of the 
cement, which process commenced during the second dentition 
(at the age of seven or eight years) and twenty-six years later 



* Quarterly Journal of Dental Science, 1851 
f Gazette des Hopitaux, 1868. 



316 NEW- FORMATIONS. 

was succeeded by a necrosis which was ushered in by the appear- 
ance of an abscess. The tumor attached to the radical portion 
of a wisdom tooth, illustrated in the Atlas, Figs. 28 and : 
an osteo-odontoma which was developed in connection with the 
formation of the dentine of the roots, and differs essentially in 
structure from the two cases which have been cited. 

The cement, even when it is hypertrophic, as has already 
been observed, in consequence of resorption following inflamma- 
tion or hypertrophy of the periosteum of the root acquires ■ 
rough outer surface which is not to be confounded with the 
roughness presented by osteophyte-like outgrowths on the ce- 
ment. In consequence of the resorption accompanying inflam- 
mation of the root-membrane, a thorn-like process sometii 
formed at the radical extremity, which is merely the remnant 
of the apex and upon which the indications of resorption may 
be identified; such a process, if not carefully examined, may be 
mistaken for a thorn-like exostosis. 

Root-membrane. — New-formations of this membrane occur 
either primarily or secondarily in the form of localized thicken- 
ings or tumors which are to be classed with the fibrous, sarcom- 
atous, or cancerous. E. Magitot collected eighteen cases in a 
monograph upon this subject.* In his opinion, the tumors, under 
certain conditions, originate in the intervals between the iv 
involve the greater portion or the whole of the root-membrane ; 
they vary in size between that of a pea and a hazelnut : they 
are very variable in form, occur only upon the bicuspids and 
molars, at any time of life, and generally are single, but in quite 
rare cases, several tumors, independent of each other, are met 
with. From examinations conducted by Robin. Magitot con- 
eluded that a substance, which is a modification, more or li- 
the root-membrane, always forms the stroma and the funda- 
mental tissue of the alteration, and he divides the tumors of the 
dental periosteum into five groups, as follows: 1, fibrous, in 
which there is an hypertrophy of the normal elements with a 
predominance of fibrous tissue; 2. fibroplastic, with a predomi- 
nance of nuclei, or spindle-shaped cells ; o, epithelial (epithelioma. 



* Meraoire sur les Tumeurs du Pericyte Dentair 



ROOT-MEMBRANE. 317 

cancer of authors), with flattened, sometimes multi-nucleated cells 
in the condition of fatty degeneration ; 4, tumors with myelo- 
plaxes, the principal constituents of which are multi-nucleated 
cells ; 5, tumors with cytoblastions, in which free nuclei with 
granular contents and with no nucleolus are the prevailing 
elements. 

I have, likewise, observed the first three of the above-quoted 
developmental forms; the fourth, where the myeloplaxes (multi- 
nucleated, gigantic cells) are the principal elements, apparently 
are of quite rare occurrence, since Magitot cites only one obser- 
vation of the kind. The fifth group I class with the sarcomata 
and the nuclei are not free, but are surrounded by a layer of 
protoplasm. Between the fibrous, more consistent tumors which 
consist, principally, of spindle-shaped cells with a well-marked, 
fibrillated intercellular substance, and the sarcomatous which 
contain, principally, small cells, with scanty, ill-defined fibrillated 
intermediate substance, there are mixed forms in which the 
tumor presents a predominance of the fibrous element in some 
places, and in others, of the sarcomatous. A purulent infiltra- 
tion sometimes takes place in the peripheral portions of the 
new-formation, when it becomes implicated in an inflammatory 
affection. 

Cancerous tumors of the root-membrane I have observed only 
in association with cancerous infiltrations of the surrounding 
parts, in which cases the root-membrane was thickened, more 
or less, or marked with pale, smooth, conical protuberances (with 
epithelial cancer). Cross-sections present a wide-meshed net- 
work of thin connective-tissue bundles, the meshes of which are 
filled with agglomerations of flattened, polymorphous cells, con- 
taining one or two large nuclei and a generally minutely gran- 
ular, cloudy protoplasm. Numerous layers of these cells are 
found upon the surface of the cones. In connection with cancer 
of the bone of the upper jaw, I have also observed cancerous 
infiltration of the periosteal membranes of the front teeth. 

Magitot divides the symptoms induced by tumors of the root- 
membrane into those which are local, confined to the affected 
part, those which have their seat in the adjacent part, those 
arising from affections of the terminal branches of the fifth pair 



318 NEW- FORMATIONS. 

of nerves, and those which are general and are occasioned, com- 
monly, by the intensity of the local disturbance. The local 
symptoms, which sometimes are the only ones, indicate, as a 
rule, the commencement of the disease ; the affections of the 
nerves usually succeed and, apparently, are dependent upon the 
former; sometimes, however, these are the first to appear, and 
continue to be the only symptoms.^ The general symptoms are 
the last to make their appearance, and are developed, also, during 
certain periods of the disease. 

The local symptoms simulate those of chronic inflammation of 
the root-membrane, and the existence of a tumor of the root- 
membrane can only be determined as probable when the carious 
or non-carious tooth has become loosened and dislocated, 
chronic, circumscribed suppurations (Eiterungsherde) produce 
these results; even the occasional consecutive appearances pre- 
sented by the gums, as swelling and suppuration, occur alike 
with chronic inflammation and with tumors of the root-mem- 
brane. An acute inflammation of the periosteal membrane may 
quite readily be discriminated from the latter. 

The progress of the tumor is quite slow, being prolonged 
during many months ; there are exacerbations in the inflam- 
matory symptoms, sometimes severe pain and very acute 8 
tiveness which is manifested in chewing or bj contact with 
anything. Magitot observed, also, a certain degree of disturb- 
ance of vision in cases complicated with orbital neural- 
tinnitus aurium and partial deafness in connection with neuralgia 
in the ear. 

Magitot, in an appendix to his monograph, gives a descrip- 
tion of polypi of the dental periosteum, accompanying caries, 
which are attached by means of a pedicle to the neck of the 
tooth and are composed of the same tissue as the normal peri- 
osteum but in an hypertrophic condition ; he did not meet with 
epithelium or myeloplaxes in these. 

These polypous outgrowths upon the necks of teeth, which 
occur in connection with caries, indeed tumors upon the carious 
roots, also, are especially liable to be confounded with prolifera- 
tions of the gums, when the latter, in consequence of partial 
resorption of the alveolus, extend to the neighborhood of the 



GUM. 319 

radical apices, become inserted between the roots or are attached 
to the necks of the teeth. The well-marked papillary structure 
of the proliferating gum, together with its epithelial covering, 
afford quite positive grounds for its distinction from the former 
affection. 

Gum. — Papillomata of the gum are, essentially, localized 
hypertrophies of the papillary portion ; generally they are asso- 
ciated with caries and are located upon the facial surface of the 
gum; their diminutive conical elevations form dome-shaped en- 
largements and present an analogy with acuminate condylomata. 
The remarks which have already been made in connection with 
hypertrophy of the gum are applicable to the structure of 
papillomata. 

Sometimes proliferation of the submucous connective tissue 
of the gum coexists with that of the papillary portion, in which 
cases the tumors acquire larger dimensions and firmer consist- 
ence.* 

Fibromata of the gum occur in the submucous connective 
tissue in the form of projecting, superficially smooth, compact 

* Suiter (Gay's Hospital Reports, series iii) reported the following inter- 
esting case from the practice of W. S. Granger. In a man fifty-seven years 
of age, the upper first bicuspid being loose was removed; to all appearances 
the tooth was sound, as, also, was the surrounding guv.:. Four months later. 
a slight unevenness and swelling was noticed upon the same side of the palate, 
extending from the inner alveolar margin of the gum, at the point where 
the bicuspid was located, in the direction of the arch of the palate and cover- 
ing a space about as large as a finger nail. While smoking, this place be- 
came sensitive but at other times it was not painful. After cauterization, 
distinct papilla: were developed. Eleven months after the extraction of the 
bicuspid, the tumor had attained half the size of a walnut and spread from 
the alveolar margin upon the hard palate towards the median line. Its 
color, a creamy-white (probably from the exfoliation of the epithelium), con- 
trasted with the dark-purple of the investing mucous membrane and between 
the two was a sharply defined boundary. In extirpating the tumor, Cock 
found it so firmly united with the periosteum of the hard palate that it was 
necessary to remove the sound portion of the latter which was beneath the 
tumor. Three months later the wound was closed by a healthy cicatrix ; 
there was not the least trace of glandular swelling and no recurrence of the 
tumor. Two small pieces of bone exfoliated, probably in consequence of the 
separation of the periosteum and the free cauterization. The tumor was 
composed of fibrous tissue, and its outer surface presented, everywhere, 
large, closely packed papillae. 



320 NEW- FORMATIONS. 

tubercles, which slope away towards the surrounding t ; - 
they are by no means of rare occurrence, especially those of 
smaller dimensions, and are composed of firm bundles of con- 
nective tissue with numerous interlacements, and imbedded cells. 
Linhart* extirpated a fibroma of the submucous connective 
tissue, nearly as large as a hen's egg. 

The sarcomata, likewise, have their seat in the submucous con- 
nective tissue of the gum ; they project in the form of tolerably 
firm tumors, as large as a pea or bean, and inclose, in their 
outermost layers, roundish, in the deeper, spindle-shaped cells, 
together with a scanty, fibrillated basis-substanc 

Angiomata (vascular tumors) are of rare occurrence and some- 
times give rise to hemorrhage which endangers life. 8 ilterf re- 
ported a new-formation of this kind, which 
numerous convoluted bloodvessels and connectiv< The 

surface of the tumor, which was tabulated, located upon the 
of a tooth and as large as the berry of tl 
cherry, was covered with papillae like those of the gam and 
with epithelium. The latter condition Berves to indicate that 
the new-formation was seated in the Bubmucoufl 
of the gum and not, as alleged, in the dental periosteum. 

Epithelial cancer sometimes occurs primarily in the gum and 
generally is met with in the vicinity of the mol 
all, minute knotty elevations are developed, which i: 
number and extent and spread to the Bubmua etive 

tissue, dental periosteum, alveolus, and alveolar ; The 

epithelium undergoes notable proliferation and imparts a br : _ 
color to the knots; it also dips down to a consideral 
into the substance, where the familiar r :-like 

groups of flattened, often distinctly ribbed cells are met with. 
Sometimes the papillae of the gum, als< i ierablv in 

length and breadth, and the cancer acquires the appearau 
a succulent wart which finally ulcerates. Schuh I the 

origin of the epithelial cancer upon the internal buccal surface. 



* "YTurzburger med. Zeitechr., Bd. II. 

f Trans, of the Path. Soc . 1864. 

t Pathologie and Therapie dor Pbeudoplaameo. 



MUCOUS MEMBRANE OF THE MOUTH. 321 

usually in the vicinity of the last molars. Here, also, he says, 
it maintains, for a time, the character of the broad (flach) cancer, 
that is, of a form of cancer which increases only in its extent of 
surface, not in depth, remains superficial, therefore, resembling 
a granulating surface, and slowly destroys the organic parts.* 

Medullary cancer sometimes spreads to the gum from the 
adjacent parts, but it can hardly be said to affect the former 
primarily. 

Mucous Membrane of the Mouth. — Notably projecting pro- 
liferations of this membrane are met with, now and then, in con- 
nection with caries, adjacent to the lingual surface of the gum, 
particularly in the vicinity of the upper molars; they contain a 
layer (one-half centimetre and upwards in depth) of acinose 
glands beneath a turgid corium, and are to be regarded as ade- 
nomata. The importance of these glandular enlargements, in con- 
nection with the carious process, will be considered further on. 

A. Forsterf not infrequently observed a swelling of the glands 
of the oral mucous membrane, together with a transformation 



* Under this head is to be classed the remarkable ease of a papillary 
tumor upon the alveolar margin of the right lower jaw, in a man eighty 
years old, which came under the observation of W. Fergusson, and was re- 
ported by J. A. Salter (Guy's Hospital Reports, series iii). The tumor, 
having the appearance of long-macerated flesh which had acquired a bad 
color, was removed, and fourteen days later it returned presenting the same 
character, so that it became necessary to repeat the operation. The patient 
died from old age, as it was alleged, soon after this operation. It was stated 
that there was no swelling of the lymphatic glands in the neighborhood, and 
the tumor was unconnected with the bone. Salter found an aggregation of 
papillae, pointed at their free extremities and united together at their bases, 
many of which were nearly an inch long and resembled the papilla- filiformes 
of the tongue, while others were similar to the papilla? fungiformes. The 
mass consisted almost entirely of pavement-epithelium, and the cells were 
also arranged in the form of birds' nests, as in epithelial cancer. The 
elongated filiform papilhe were striped longitudinally and were readily 
separable into smaller hairy processes ; their edges were composed of very 
compact cells which by themselves presented no evidence of an epithelial 
character, while, on the contrary, the more superficial cells were decidedly 
epithelial. He was unable to distinguish any limiting layer of the papillae, 
nor any vascular loops in them. The basis of the new-formation was com- 
posed of fibrous tissue. 

f Handbuch der pathol. Anat., 2 Aufl., Bd. II. 

21 



322 NEW- FORMATIONS. 

of the glandular secretion into a mucilaginous or colloid m 
When the acini are confluent, cysts are developed, containing a 
mucilaginous mass in which, in certain cases, larger or smaller 
calcareous concretions may also be found at a later period. 
He met with the latter tumors also adjacent to the gum. I ha 
also, repeatedly observed them in the latter location, and hi 
found the mucous glands degenerated in the mariner deseril 
occasionally, the development progressed to the formation of 
young, gelatinous connective tissue. 

The white excrescences upon the mucous membrane of the 
cheeks, lips, and palate, described by Schuh,* belong to tl 
gory, in the opinion of Forater. The former <]■ 
white, curved folds, which project from one to four lii 
two to three lines broad, and may acquire a length of 
inch. They terminate occasionally in discrete knots the size of 
millet-seeds. Sometimes several folds of thia deacripti 
found in close proximity. Their outer surface' is t 
smooth or minutely granular, and their like that 

the broad condylomata. They are never painful. Tin 
plete development occurs within a few weeks. In two 
they disappeared spontaneously in a few months: in a third, 
during the external and internal use of iodine; in a fourth, the 
affection had lasted several years, and in c: iwly all 

in a uniform manner. The affection returned after extirpation. 
Schuh did not investigate them very closely, and. there!' 
their pathological classification is. as yet. undecided. 

Alveolar Processes.— It has been customary of lal 
epulis with the diseases of bone, and t«. understand then 
tumors growing from the maxillary periosteum, particularly 
from that of the alveolar processes, and from the bony Bui - 
of the latter. Virchowf considers it best t<> employ the term 
epulis only in a topographical sense, to signify a tumor of the 
alveolar process. This restriction of the term. I con- 

venient in that it enables us to speak oi' epul 
myxomata, &c. 

Epulis, in the restricted sense of an affection of the ] 

* Pseudoplasmon. lg 

f Die krankhaften Geschwulste, Bd. II. 



ALVEOLAR PROCESS. 323 

originates in an irritated condition of the periosteum and bone. 
Traumatic causes, e. g., crushing and splintering produced in 
extraction, particularly of the milk and permanent bicuspids 
and molars, in all probability give origin to it in some cases. 
Positive proof of a trauma is difficult to obtain, however, in 
many cases. A congenital or acquired obliquity of one or 
another tooth may also be regarded as an occasional cause. 
Carious roots are said to be a frequent predisposing cause. 

Schuh regarded epulis as a local affection which may occur 
at any period from the second year after birth, even to old age, 
and in either sex or with any habit of body. It occurs, how- 
ever, more frequently in young persons. Many writers assert 
that it is of more frequent occurrence with females than with 
males, and is met with more often on the lower than on the 
upper jaw. 

The tumor is distinguished, in situ, as a firm, immovable, 
convex, knotty protuberance of variable size, covered with red- 
dened mucous membrane; it spreads over one or more teeth, 
dislocates them from their normal positions, and loosens them 
so that eventually they fall out. As a rule, it does not occa- 
sion any pain in the teeth, nor do the latter present any per- 
ceptible anomaly after extraction. Generally its site is in the 
vicinity of the teeth which have multiple roots. 

When the epulis, in the course of time which may be pro- 
longed for several years, has attained considerable size, so that 
it produces a notable bulging upon the facial surface, a distor- 
tion of the nostril, a deviation of the angle of the mouth and of 
the external angle of the eye, and spreads upon the lingual side 
as well, hemorrhages easily occur, in consequence of the hyper- 
a*mic condition of the veins of the tense superjacent gum, and 
erosions are produced, which result in ulcers that are, sometimes, 
disgusting in appearance and emit a foul odor. If the disease 
be neglected, even perforation of the external skin may ensue, 
a portion of the tumor may suppurate and then life itself may 
become endangered. In consequence of the irritation produced 
by the disease, the lymphatic glands in the superior cervical 
region sometimes become swollen. 

Epulis fibromatosa generally has a firm, compact, tough, 



324 NEW -FORMATIONS. 



fibrous, slightly succulent texture, and towards it? broad ] 
portion presents either scattered agglomeration? of calcareous 
grains, or a trabecular new-formation of osseous substance. The 
fibrous basis-substance is abundant, and there are bundl- 
elongated fibres which interlace extensively. The long dia 
ters of the spindle-shaped connect iv 

with the direction of the fibres. Where tl ...n,l 

processes, the latter unite to form a network. Chain-like 
groups of granular ovoid cells are imbedded in the parenchj 
where they form numerous layers. The ag|j ■' cal- 

careous grains are surrounded by tough fi : the cal- 

careous salts may be extracted by W 
when there remains the organic basis of the 
cases, therefore, the process of bone formation | 
to the stage of excretion of cab- 
tively few places isolated grou] pith. 

When the osseous substance of the base of the to 
growth from the periosteum, retifoni 

met with, imbedded in the bundles of connective I bich 

become less conspicuous towards the periphery of th. 
(Atlas, Fig. 13G). Isolated groups of delicate tral 
are found. In order to display the newly-form< 
work of the osteoid tumor, it should 1m- mar 
_ When tumors of this description have attaii 
size, it is also found that separate portions acquire a gelatii 
(myxomatous) character, and in these portions nunc 
of cells are discernible within a delicate, trabecular 3 

The submucous connective tissue of the gum is in imm< 
relation with the epulis, and the gum is subj iiderable 

tension as the tumor continues to grow. The papil] 
notwithstanding its remarkable mirror-lik 
still readily be identified (Atlas. Fi« 

As the development of the tumor pr _ sses, tl urn is 
stretched to such a degree that it becomes necrosed. I, 
quence of the unavoidable irritation and foulness, 
food, hquids, &c, purulent infiltration of the tumor ensues in 
connection with the above-mentioned offensive ulceration, a con- 
dition of things which may lead to an erroneous interpretation 
of the tumor as one of a cancerous nature 



ALVEOLAR PROCESS. 



325 



In cases of epulis in which there is a predominance of the 
sarcomatous, to the exclusion of the fibrous element, an abun- 
dant cellular structure is presented to view, which sometimes 
attains such a preponderance as to displace, almost completely, 
the fibrillated substance, and we find only aggregations of large 
spindle-shaped cells, together with encapsulated groups of round- 
ish cells, generally with a single nucleus, and a scanty fibrillated 
substance. There is a notablj- frequent occurrence, even in the 
fibrous epulis, of flattened, large cells which present variously 
shaped processes, a minutely granular protoplasm, and inclose 
two, twenty, and even many more, oval nuclei, and have been 
described by Robin as myeloplaxes (medullary plates), and not 
as cells; he found these in normal marrow, particularly in that 
of young, growing bone. This view, however, has not met with 
very general acceptance. Paget called these formations, multi- 
nucleated cells, and Yirchow designates them as multi-nucleated, 
gigantic cells. Since the gradual multiplication of the nuclei in 
a series of these elementary organs may easily bo traced, and a 
progressive division of the nuclei, together with a corresponding 
increase of the protoplasm, may be identified with very high 
magnifying powers, and since there is nothing to indicate the 
occurrence of casual fusion of cells, I 
consider it to be settled that they origi- 
nate from uni-nucleated cells. These 
flattened, gigantic cells are disposed be- 
tween the fusiform cells and, frequently, 
fall out from sections of the tumor, leav- 
ing corresponding empty spaces(Fig. 01). 
Yirchow regards them as heteroplastic 
formations which arise from the pro- 
liferating elements of the periosteum. 
This heteroplasia, according to him, does 
not involve the idea of malignancy, even 
in the narrowest clinical sense; at all 
events, he is not aware of a case where 



Fig. 91 * 




* Fig. 91 shows a section from an epulis sarcomatosa, which includes in 
its basal portion numerous bony spicules, and contains in its fleshy portion 
interdigitating fusiform cells with prominent nuclei, which, also, surround 



326 NEW- FORMATIONS. 

the process extended by metastasis from an original epulis to 
internal organs, or where it spread even to the nearest lym- 
phatic glands. 

Several varieties of epulis sarcomatosa are distinguished. 
According to their seat, E. Nelaton* has divided such tun; 
into two forms, which he describes as ptri-os* U9€ 
ostique/und as intra-ossewe, both of which, in his o\ 
from an hypergenesis of the medulla of the bone. Th 
varieties, in the opinion of Virchow. evidently correspond with 
the two forms of sarcoma, the periosteal and myeloid. He op- 
poses, with reason, the view of Nelaton, that the; 
invariably, by an hypergenesis of the medulla of tin 
he says, it is not uncommon for the tumor to han 
basal portion which forms a considerable elevation beyond the 
surface of the original bone, and the softer portion <»f the tin 
which contains the myeloplax : rated from the 

surface of the old bone by this bony ba had the 

opportunity of observing such an i 8 coma, but am of the 

opinion that our present knowledge in I 

propagation, and signification of the multi-nucleal tttic 

cells is still too defective to enable us to form a definite idea in 
respect to their origin. 

If we examine, before and after maceration, i which 

grows in the medulla of the bone, together with the tootli which 
is inserted into the tumor, we find that ti ill of tie 

maining bony framework are dilated and filled with a tolerably 
consistent new-formation. The latter contains nun 
and fusiform cells, besides bloodvessels with thick walls, wl 
external coats swarm with proliferating cells. The 
trabecule which are still retained in the new-formation und< _ 
a gradual resorption which, also, visibly involves the ah 



multi-nucleated, gigantic cells, so-called myeloplai - 

present short, blunted or pointed processes, vary in size, and inclose, within 
a protoplasm of minute granules, numerous oval and multifarious 
nuclei. The transition from uni-nneleated ovoid t<> the la »y In- 

followed out. The section shows several vacuities, th 
which have fallen out. Magnified four hundred diam 
* Virchow, op. cit., p. 313. 



ALVEOLAR PROCESS. 327 

the tooth. If the new-formation comes into contact with the 
periosteum of the root, after the complete resorption of a portion 
of the alveolus, the tooth, of course, becomes loosened in its 
socket. 

When the epulis is confined to a small portion of the alveolar 
process, the operation proposed by Salter, to extract the cor- 
responding teeth, with the view of preventing a recurrence of 
the superficially-extirpated tumor by means of the resorption of 
the dental alveolus which ensues after the extraction, may some- 
times be of service. In many cases, however, the removal of 
the teeth will have no effect in inducing the involution of the 
tumor, if the latter be a myeloid and deeply rooted, and the 
germs are allowed to remain and to continue their development 
after cicatrization of the alveolus is completed. Schuh states 
explicitly- that teeth which have become loosened by the disease 
not infrequently are extracted before the patient has any sus- 
picion of the existence of the affection. If the tooth is only a 
little loose, we may be assured that the bony alveolus is involved, 
and the tooth should be extracted ; the degenerated portions 
should be excised with a strong knife and the cut surfaces 
thoroughly scraped or carefully singed with the actual cautery. 
He lays stress, therefore, upon a radical extirpation. 

Osteo?nata or exostoses of the alveolar process usually are con- 
sidered under the head of hypertrophies in the manuals of den- 
tistry. They are not by any means of very rare occurrence, 
and are met with frequently in the cadaver, in more or less ad- 
vanced stages of development. 

They present manifold variations in size, from that of minute 
knots to that of excrescences as large as millet-seeds, peas, or 
beans; the latter sometimes coalesce and form a ridge or crest. 
The diminutive forms often disappear during life, or are mistaken 
for callosities of the gum and are not recognized except upon 
the skeleton. They are less likely to attract the attention since 
they occasion no annoyance. Upon the alveolar border of the 
labial side of the lower jaw, particularly in association with the 
firm structure of the jaws and teeth in elderly people, or with 
closely-approximated or overlapping teeth, I have frequently 
found tuberiform excrescences, two to three millimetres in diam- 



328 NEW -FORM AT I 



etei; and one millimetre thick, which were trai 

pendicular direction by shallow v.i 

compact and only in very rare c 

ments than those mentioned. 

is not uncommon, in which c y form r 

hump-like elevations corresponding j n ] 

different dental roots. 

Upon the lingual side of the lower jaw, tb t.-s at- 

tain larger dimensions. Tin- cum i 
138, shows compact protuberanc 
sent depressions and grooves upon their 
surfaces, are attached by a broad ba 
just beneatn its margin, and are 
and first molars. The anterior Begmenl 
presents no exostosis, and upon the j - 
the second molars and wisdom t< 
bone. In this case, 
more than five millimc: 
served, they were considerably larger, [n tl, 
are two flattened protuberances npoi 
anterior segment of the maxillary a] 
lateral incisor and canine on eil 
large osteomata, one behind the bicusp 
either side. The surface of tl, 
whichmeasuressi.xreenmilli.net, 
eter, is smooth, that of the one on ti. 
of nineteen millimetres, is traversed by , 
and has a diameter of seven milli 

A bony ridge extends upon either sid< 

of the alveolar process, from the larg 
ot the second and third molars. 

I have met with osteomata, appea 
dropped upon the alveolar pi 

the facial surface and corresponding to tl, 

canines, bicuspids and molars. Thev occur either ia the for- 

of an exuded, as lt were, quite, allll . t! ..* 

white osseous mass which covers the alveolar p, .' it8 

margin, or, especially in the region of the n 



ALVEOLAR PROCESS. 329 

of p;id-like elevations, the size of a lentil or even larger, which 
have a broad base, sometimes project beyond the alveolar mar- 
gin, are polished upon their outer surface and, now and then, 
are traversed by Beveral vascular grooves. In other cases, we 
find merely a projecting bony ridge which unites the alveolar 
bordi 

Microscopic examination of sections of these growths Bhows 
that they are composed of the compact osseous tissue of the 
cortical Bubstance. The lamellae are disposed in the form of 
arches and are very uniform ; the vascular canals form a series 
of flattened are-, w ith oblique anastomoses, and, generally, a 
small diameter | Fig. 92). Hence arises the notable compact 




and white appearance of the osteoma. The alveoli are not in- 
volved in the process and, therefore, the teeth retain their normal 
position. 

Close examination of the osteoma establish* id doubt 

the fact of an interstitial in many pi a 

We find, namely, interposed bone-corpuscles, isolated in some 

and grouped together in others, which are separated from 

the original Bystems by a hyaline, indented or festooned, dividing 



* Fig. 92 -how- an osteoma from tin- lingual wall of the anterior Bcgment 
of a lower jaw. The tumor forma an elevation upon the wall, seven mil- 
limetres in height, rises abruptly upon one side and upon the other presents 
a more gradual slope, I;- - trface is Bmooth, the osseous tissue throughout 
i- compact lil<<' that of the cortical substance of the bone. The narrow 
Haversian canals are disposed at tolerably uniform distances from each 
other, and their direction corresponds with the arched formation of the 
tumor. The commencement of the spongy tissue is Bhown at the broad base 
of the tumor. Magnified three diamefa 



330 NEW- FORMATIONS. 

layer. The extent of these new interstitial Bystems ible; 

they are wanting in uniformity and are disposed aroand the 

vascular canals, or penetrate, are wedged in, as it i 

the rows of the old systems which, frequently, present a _ 

cloudiness and correspond with parte in which 1 • 

begun. 

The peripheral, very compact zones of the Buperfi 
osteomata not infrequently contain i ICU ]j 

which extend, in nearly parallel ro the int. 

the periphery, in a direction oblique to thai of t : 
planes. They are wider than the ordinary b 
a straight course, bifurcate at acute an 
in immediate connection with the b 
in free extremities at the periphery. I am oc 
or not they have any connection with SI 
have become acquainted with quite 
canaliculi in hypertrophic cement, and in both 
give to the corresponding portion of th< 
striped appearance, recognizable even with quit* 
powers. 

The origin of these localized proliferati,,, 
stance, which are ushered in by an hyperplai 
peristeum of the alveolar pr st iH and, 

fact already mentioned, that they are fonnd in 
powerful jaws and strong 

overlapping teeth, suggests the opposition that • 
irr.tat.on is induced by the act of n,:, 
cases, 1S conducted with s.uh fore, 
d,s P lacement of the teeth in the npper j. 
keuptds _and molars, and ,n abnormal lingu., 

tomat :r; jaw - ww » «**«.* 

o t omata would become evident Syphilis, 
of tartar, or canes take no pan in theii 

They requtre treatment in exceptional cases only 

of then excess.ve s.ze. They do not give | th 

movements of the tongue are interfered with. 



CYSTS OF THE JAWS. 331 

proliferations afford a lodgement for particles of food, or they 
produce a disfigurement. They may also form a hindrance to 
the adaptation of sets of artificial teeth.* 

The spongy tissue of the alveolar process may, likewise, acquire 
an hyperplastic condition, whence an j becomes devel- 

oped, which occasions resorption of the alveolus, dislocates the 
tooth from its normal position and, eventually, loosens it so 
much that it falls out. The en 08 1 08 is forces the lingual and 
facial walls of the alveolar process farther apart, or produc 

wider separation of adjacent teeth and. therefore, exerts an ill 

effect upon the entire set of" teeth. 

Cysts of the Jaws. — Under this head are comprised those 
hollow-formations which have their seat, principally, in the spongy 
tissue of th<- alveolar p embracing upon one Bide the facial 

or lingnal surface of one or more roots, while, upon the other, 
as they increase in extent, they protrude and occasion a partial 

resorption of the cortical substance of the b 

rabelli observed cysts in both the upper and lower jaw, 
without, however, recognizing them is such; he described them 
in his lectures as Eydrops Antri Highmori and cellulae dentis 



* Bourdet (L'artdu Dentiste, 1757) observed five or six cas itoses, 

of different Birea up to that of a pea, upon the facial wall of the alveolar 
both the upper and lower jaw, and corresponding in locality to 
that of tin- incisors ami canines. They occasioned no pain, but produced a 
disfigurement. They returned after removal by mean.- of the bone-forceps, 
but disappeared under the application of the actual cautery. Tomes remarks 
that in one case only ha> he seen hypertrophy of the alveolar process attended 
with inconvenience. In this case -'the whole of the alveolar bone was 
greatly enlarged ; it projected upward- in the lower, and downward- in the 
upper jaw, carrying before it a red ami thickened gum and concealing within 
tin- groove formed by the lingual ami labial portions of the alveolar ridge 
the corresponding surfaces of the whole of the teeth. The thickening in the 
front part of the mouth was so great that the lip- could not he closed. At 
the back part of the alveolar arch, the thickened and elevated gums of the 
respective jaws, although mutually flattened, were not sufficiently depressed 

by the action of the jaws to allow the molar teeth to come in contact. The 
patient was a half-witted Btrumous child, whose age did not exceed thirteen 
yen'-, and whose general appearance justified the assumption that the disease 
was but a local manifestation of the presence of a strumous diathesis." No 
treatment was undertaken. 



332 NEW- FORMATIONS. 

ai)d from them he drew a conclusion r< _ the s t r i , 

the dental periosteum which he held to be 

Albrecht,* in nine thousand three hundred and fifty | 

treated by himself, met with only seven ca 

tion beneath the oral mucous membrane ujh.ii the op] 

lower jaws, and in every case the tumor waa situated behind 

bicuspids. 

Cysts are met with more frequently in the upp< in the 

lower jaw, and are more frequent in front of than the 

bicuspids.f 

Since, in the earlier stages of their owth 

is inconsiderable and their inci 

painful sensations, they escape observal j til, 

in consequence of a more rapid increase in their rolumi 
tention and bulging of the maxillary wall i 
first time, they are perceived by the patien 
date their origin from the time when they fin 
and, usually, consider them to be 
periencing no pain from them, they do not applj 
advice in regard to them, until it is found tl 
the employment of emollients, the Bup] 

crease in size and show no disposition I ,th, 

sometimes six months and more, are alio* 
time when they are first noticed, and. 
comes perceptible even externally will 
companied by redness or heat of the skin. 1 
unable to assign any reasons for their occun 
tion, a bulging, from the size of a hazel-,,, 
walnut, is found, usually, upon the facial wall of the jan : i( 
sharply defined, not movable, impart> the ■ 
tmn, and the portion of the maxillary wall which 
the tumor feels like parchment and ere; 
pondmg to the most prominent part, usually, 
it this is extracted, the contents of the t, 
ated immediately by means of firm pressure , 



* Klinik der Mundkrankheiten 
tHeiderundWedl in the Deutsche Viertelj.f. 2 



CYSTS OF THE JAWS. 333 

finger or after puncture of the wall of the cyst within the socket 
with a sharp instrument. The fluid which escapes, usually, is 
albuminous, viscid, ropy, yellowish, and clear. 

It depends upon the situation of the cyst, whether the outer 
or inner wall of the jaw is distended the most ; in the upper jaw 
the facial wall, usually, is the one involved. When the cysts of 
the upper jaw are developed in the region of the bicuspids and 
molars, they project even into the antrum. The cystic growths in 
the mucous membrane of the latter will be considered farther on. 
arded eruption, especially of the wisdom teeth in conse- 
quence of their oblique position may be the predisposing cause 
of a cyst-formation, and in Midi cases the question arises whether 

the dental sac degenerates into a cyst which incloses 1 1 1 « 

tarded tooth or whether the growth of the tooth in an abnormal 
direction exercises an irritation upon the surrounding osseous 
Bubstance by reason of which the latter becomes abnormally de- 
veloped in the form of a e\ mentions two instruc- 
tive cases, from Volkmann's clinic, of very extensive cysts of 
the lower jaw ; in one of them, the right wisdom tOOth was located 

upon the posterior wall of the cyst : its roots were imbedded in 
a peculiar manner and, obviously, in consequence of a deficiency 

ol* space. In the Otbj the crown of a molar (large?) was 

found projecting into the cyst from the lingual side of its ante- 
rior portion, [ts roots were small and bent to one side, evi- 
dently in consequence of a want of space. The tooth, finally, 
was displaced so tar in consequence of the gradual distention of 

the jaw to the colossal Cyst, that it was located at least an inch 
ami a half below the level of the rest of the teeth of the lower 
jaw. 

The mode of development of cysts of the jaw has not yet been 
determined, and further anatomical investigations are necessary 
in order to elucidate this subject. We communicated, in the 
paper cited above [vide, also, Atlas, Figs. 133 and 134), the 
results of an anatomical examination of a cyst in the alveolar 
process of the upper jaw, behind the root of the right central 
incisor. The development of the cyst was not sufficiently ad- 

* Inaugural dissertation, 18U9. Deutsche Yiertelj. f. Zahnheilk., 1870. 



334 NEW- FORMATIONS. 

vanced to occasion a protuberance upon the lingual surface of 

the mucous membrane of the mouth, and. consequently, it had 

escaped clinical observation. A portion of the cortical la\ 

the lingual wall, five millimetres in extent, was wanting, and 

the corresponding portion of the cyst wall, consequently, 

into immediate relation with the subcutan 

of the gum; before long, therefore, a protuberance would have 

become perceptible. Moreover, the growth of th< 

the osseous tissue was indicated by the fact that a new, minute 

cyst was located laterally upon the fibre 

Fackeldey,* with special reference to this case, tl 

grounds for considering the question whethei t the 

alveolar process, which are lined with a meml 

to an anomaly of development, a d i.-ntal 

sac or a lateral budding of the enamel germ. VVil nying 

the possibility of the connection 

tion or follicular cysts, it may 1 

tion to this view that both simple and compoun with a 

fibrous lining are met with in other bones, in the 

upper jaw, especially, are developed commonly u] 

side, a locality with which the occur] 

tion cysts is scarcely compatible. 

In several cases, I have found the lining 
tough, compact, and coated upon its internal surfa* 
layer of epithelium, consist! _ - vera! lamina 
nucleated cells which, frequently, interlocked with 
means of blunt pro ; ] s are ; 

duction of the serous, viscid or gelatinous fluid, whih 
tinuous proliferation of the fibrous membrane, whir 
with wide bloodvessels with thin walls, 
resorption of the bone. Sometimes, also, tl, 
seat of an inflammatory process and. in Bach cs 
puriform fluid. 

When the cyst attains such magnitude as to fa 
teeth, extend beyond the limits of the alveolar 
sion a resorption of its spongy tissue, the ah 

* Op. cit 




OSTEOPHYTES UPON THE JAWS. 335 

sponrling teeth become involved simultaneously, the latter are 
loosened, dislocated, and their connection with the alveolar 
borders is broken. The re- 
sorption of the bone occasioned 
by the extension of the cyst, 
takes place upon both the 
facial and lingual surface, and 
effects a not inconsiderable 
breach in the substance of the 
bone (Fig. 93). The margins 
of the parts where resorption 

(usure) has taken place, are serrated, the distended facial wall is 
transparent, thin as tissue-paper, is perforated by numerous, 
minute foramina for the | Is and, upon its inter- 

nal surface towards the cavity of the cyst, presents extensive 
irption excavations which have frequently been 
mentioned in the preceding j»-i_ 

-•an only be confounded with other affections which 
-ion Bwellings in the jaws, as enchondromata, sarcomata, 
myxomata, abscesses, and with collections of fluids in the 
antrum. An ah- iwever, may be distinguished by its 

acute course, and by the fact that the tumor formed by it is 
never so Bharply defined as is the case with oysts ; with dropsy of 
the antrum, the distention of the facial wall of the jaw is more 
uniform always than it is with cysts. In some cases, the diag- 
nosis cannot be determined accurately until after an operation. 
OSTEOPHYTES DPON THB Jaws. — Sometimes, in consequence 
of diseases of the teeth and, particularly, of chronic inflamma- 
tion of the root-membrane, an irritation is induced in the maxil- 

* Fig. 93 shows a cyst of the right upper jaw, embracing in its extent both 
incisors and the canine. View from the cavity of the mouth. It has an 

oval form and a lone; diameter of two centimetres ; internally it is limited by 
tin- incisive foramen (a), and externally by the cicatrized alveoli of the bicus- 
pids (6). The labial wall is distended like a bladder (c). Considerable de- 
Btruction of tissue, which is defined by a sharply cut outline, has occurred upon 
the hard palate. A portion of the alveolar process, corresponding with the 
two incisors and canine ((f), still remains unaffected by the process of resorp- 
tion. The internal surface of the cavity of the cyst is smooth and perforated 
like a sieve. Natural size. (For the use of this specimen the author is in- 
debted to Dr. Friedlowski.) 



336 NEW- FORMATIONS. 

lary periosteum, which is attended by its tumefaction and 
sitiveness, occasions consecutive oedema and. not infrequently, 
gives rise to the formation of an osteophyte of a fine spongy 
texture. 

If a series of macerated jaws, which 1 
teeth, be examined, several of the- ths will usually l»c 

found, in the form of cribriform, un '-rally 

adherent to the facial Avail, more commonjy t<> th I 
jaw, and distinguished by a quite bright color. Wl 
off and examined in thin sections they pro 
substance. They are located, almost always, upon th< 
segment of the jaw, are of very rariab 

irregular outlines; their thickm :er to 

one millimetre. They occur in 

ally, spread over the entire surface of tin- maxillary wall. 
The period of puberty, together with the retarded erupt i 
the wisdom teeth, appear to 1m- especially fai 
velopment of osteophytes, and. when ritfa an in 

plete growth of the jaws, they are to be connected with m 
succulence of the periosteum. 

The case, illustrated on | ,,f partial n ,f the 

lower jaw, which occurred in connection with tl 
the wisdom tooth, was accompanied by an 
growth that spread over the liugnal wall of th.- jaw. v 
delicate, branching, separai- 

fig. 94.* make their appearan 

size and unite with one another. 

mellae formed in this 

forated with eharp-edg bich 

lead to the vascular - 

face of the jaw. As the I 

thickness, they ar< the 

other like the tiles on a roof, and 

marked with manifold 
indentations, which give to the whole the appea 
markably fine filagree worl | . 

ture, which forms an excrescence upon the sm, 




EXOSTOSES IN THE JAWS. 337 

Extensive, thick osteophytes, developed in association with the 
symptoms of chronic periostitis, are met with in connection with 
phosphornecrosis of the jaws. Primarily (Lorinser, Geist), they 
have a fine spongy texture, and gradually they become compact ; 
finally a new bony shell is formed, while the original, encapsulated 
bone becomes necrosed. With exacerbating symptoms, suppura- 
tion and sanious ulceration (Verjauchung) occur upon the surface 
towards the necrotic bone, and cloaca) are formed in the osteo- 
phyte, by which its continuity is interrupted. A well-marked 
case of a newly formed bony shell, which is separated from the 
necrotic lower jaw, is illustrated in the Atlas. Fig. 137. The shell 
presents fenestrated openings, the result of ulceration ; notwith- 
standing the latter process, the pr< tubercles and 
spines, and even the mental foramen, are seen to have been formed 
anew. The specimen was taken from a woman, twenty-two years 
of age, who had worked for twelve years in a match factory and 
who came under the treatment of Dr. Lorinser, on the 30th of 
March, 1S47. The disease had already existed for six months. 
She died from tuberculosis on the i!7th of August, 1847. 

Eni ix tiii: Jaws. — Virchow* proposes to limit the 

term enostosis to certain osseous growths which are developed 
from the medulla in the interior of bones ; he met with only one 
. a porous enostosis in the spongy extremity of the tibia of 
a child. lie also includes under this head the corps 0SS( ux 
enci/stc'S of Cruveilhier which arc distinguished by their great 
compactness. As the latter new-formations are of extremely 
rare occurrence and frequently escape observation on account 
of their diminutiveness, our knowledge with reference to their 
origin and development is still defective. 

Schuh has described, under the head of rare new-formations, 
a bony tumor of the left upper jaw in a girl fourteen years of 



jaw, where a fistulous opening from a tooth (a) is perceptible. The new- 
formation displays extremely delicate, shallow, channel-like, vascular 
grooves which run in various directions, interlace in a retiform manner and 
inclose minute lamellae of osseous tissue. Magnified fifteen diameters. 
(Viewed with oblique light.) 
* Krankh. Geschwiilste, II. 

22 



338 NEW -FORMATIONS. 

age, which is to be considered as a spongy enosto The im- 

movable new-formation, the size of a hen's 1 of bony 

hardness, originated in the diploetic structure and not from the 
external surface of the bone, pressed the anterior surface of the 
jaw outwards and, by its continued development inwardf 
croached upon the cavity of the antrum, a small j 
which, the superior and posterior, alone remained, i 
from the incisors on the left side as far as the maxillary tuber- 
osity and from the teeth to the lower margin of the orbi 
was not painful even when subjected to firm p The 

teeth of the affected side were normally arranged and firmly im- 
planted within the distended alveolar process. A f 
the bone was removed and presented throughout the textur 
consistence of delicate spongy bone and 
tially of a retiform trabecular stroma and a v. ry richly I 
larized connective tissue which filled the vacnil v the 

stroma. These vacuities presented no marked vai 
respect of size, hence the newly formed bony m 
quite a uniform compactness. The ] 

siderably, here and there, were more closely approximated than 
in normal bone, and the intermediate si 
places, a dirty-yellowish color. The bio 
paratively large diameters. The girl received a blow in th< 
five years previously, and this was assigned as the primary 
of the tumor. The latter was extirpated, the wound i 
rapidly without any disfigurement, and there was do recnrr 

Forgetf found, in the socket of a normal canine from the 
upper jaw of a horse, an encysted bony tumor entirely Qi 
nected with the tooth, the latter being displaced towards 
median line. The tumor was as large as an egg, irregular, and 
composed of bony substance merely : the cysl a 
suppuration. 

I have had the opportunity of examining an an 
tumor from the jaw of the horse, for which I am in 



* Oesterr. Zeitschrift fur prakt. Heilk. und Gesammelte Abh.. 
f Des Anomalies Dentaires, 1859. 



CHONDROMATA OF THE JAWS. 339 

Prof. Bruckmiiller. It was encysted, as large as a small 
hen's-egg, of the density of ivory; its outer surface was tu- 
berculated, indeed, altogether, one would be inclined to con- 
sider the case as one of an encysted, malformed tooth. On 
section, however, it displayed throughout a very compact 
bony tissue traversed by numerous, comparatively thin, vascular 
canals. 

As neither of these two encysted, compact, bony tumors pre- 
sented any dentinal texture, there are no positive grounds for 
considering them to be dental malformations, and, therefore, I 
have introduced them here provisionally. 

Choxdkomata of the Jaws. — Cartilaginous tumors are de- 
veloped from the surface of the bone or from its spongy tissue. 
Their growth, as a rule, takes place very slowly, and particularly 
is this true of the earlier stages. Pressure upon them occasions 
no painful sensation. They are consistent, acquire tolerably 
large dimensions, are intermixed with a considerable amount of 
fibrous dense tissue so that merely isolated portions display in- 
terspersions of fibro-cartilage and, therefore, are to be desig- 
nated as Jibro-cliondromata. If a partial ossification has taken 
place, they are called osteoid-ehondromnta in which, sometimes, 
calcification occurs only in circumscribed spots. If the oral 
mucous membrane becomes necrotic in consequence of the very 
marked extension of these tumors, and ulceration ensues, the 
discolored ulcer may be the occasion of confounding them with 
cancer. The more defined outline of the tumors and the absence 
of swelling of the lymphatic glands serve to distinguish them 
from cancer. Recurrence after extirpation is very common. 

The chondromata (enchondromata) which take root in the 
deeper layers of the bone, especially of the lower jaw, acquire a 
malignant nature in so far as they grow quite rapidly and give 
rise to notable, supple, even fluctuating swellings from liquefac- 
tion (Colliquescenz). The proliferating, cartilaginous tissue un- 
dergoes a marked fatty metamorphosis and solution and, in the 
liquefied localities, becomes bathed in a yellowish, viscid fluid. 
The cartilage is partly hyaline (Atlas, Fig. 140), but it is also 
met with in the form of a delicate network. As the cartilaginous 



340 NEW-FORMATIONS. 

tiss'ue encroaches upon the spongy substance of the bone, it in- 
duces a wasting of the osseous lamellae 
fig. 95* an( j eyen f ^ a i veo ] us • the correspond- 

liliiF *3fifes ^ n S tooth becomes detached, and in the 

JHi|t _gf place of the socket is found the cartilagi- 

^s^vw**** .»^^^^/ nous adventitious substance (Aftersub- 

stanz). (Fig. 95.) The pulps of the teeth are not perceptibly 
affected by the proliferation. 

Fibromata of the Jaws. — These are firm, circumscribed, 
painless, fibrous tumors, of slow growth, which are prone to 
ossify. Sometimes they acquire considerable dimensions and 
are composed of conglomerate knobs, or lobules of a uniform 
texture. According to Paget, they are of periosteal or enosteal 
origin. Virchow lays stress upon the heteroplastic nature of 
these tumors and, especially, of the enosteal fibroma — hetero- 
plastic not in the sense of malignant, but signifying a develop- 
mental process which gives rise to a tissue of a different type 
from that of the parent tissue. 

Their primary seat and mode of development are unknown. 
When superficially located, they displace the cortical, and when 
located more deeply, the spongy tissue ; partial displacement of 
the alveolar process, also, ensues, and the teeth are dislocated 
from their normal positions. As the fibroma continues to grow, 
the cortical tissue undergoes resorption, leaving a portion of the 
former covered merely by the mucous membrane, while the teeth 
are loosened and detached, from the extension of the tumor 
beneath them. 

In a circumscribed, firm fibroma of the lower jaw (Fig. 96), 
fibrous tissue alone was found towards the facial and lingual 
walls of the bone, while the central portions of the tumor were 
occupied by particles which crackled when cut with the knife, 



* Fig. 95 shows a segmentof the ramus of a lower jaw divided horizontally, 
with chondromatous proliferation in the spongy substance. The two roots 
of the first molar are divided transversely ; those of the second and third 
molars, together with their alveoli, are wanting ; a succulent, adventitious 
substance occupies their places, and spreads to the cortical layers of the bone. 
In this, numerous oval cartilage-cells are interposed in a delicatelv-fibrous, 
succulent basis-substance. Natural size. 



FIBROMATA OF THE JAWS. 341 

and conveyed the sensation of roughness. The teeth were 
notably displaced in consequence of the resorption of the cor- 
responding alveoli, their roots were inserted directly into the 
newly-formed mass, the fibrous bundles of which were in imme- 
diate connection with the periosteal membranes of the roots of 
the corresponding teeth. Further, as the fibroma continued to 
grow, it encroached upon the limits of the alveolar process which 
became flexible. 

Fig. 96.* 




The firm substance of the tumor is composed essentially of a 
confused mass of interlacing bundles of connective tissue, be- 
tween which narrow, fusiform cells, following the course of the 
fibres, are interposed at tolerably uniform intervals. The cen- 



* Fig. 96. — View from above of a fibroma of the lower jaw, from a patient 
fourteen years of age. The jaw was resected in a line extending from the 
left central incisor (a) along the right horizontal ramus as far as the wisdom 
tooth. Marked displacement of the teeth was occasioned by the presence of 
a rounded, encapsulated, firm tumor, 6.4 centimetres in length, 4.5 centime- 
tres in height and 4 8 centimetres in breadth. The incisors are inclined 
obliquely and laterally. The canine and first bicuspid are inclined still more, 
so that their summits are directed posteriorly and towards the median line 
of the jaw. The second bicuspid (b) is separated from the first by a con- 
siderable interval, in consequence of the proliferation of the growth between 
them, and the masticating surface of the former is directed anteriorly and 
towards the median line, so that the axes of the two bicuspids cross each 
other at nearly a right angle. The first molar, which is carious, presents a 
slight inclination; the second molar occupies its normal position. Two- 
thirds natural size. (For the use of this specimen the author is indebted to 
Dr. Weinlechner.) 




342 NEW -FORMATIONS. 

tral, rough spots are occupied, in places, by calcified bodies, 

merely, having a homogene- 
Fig.97* oug> polished appearance and 

Sjg| a roundish, often spherical, or 
an elongated form, and i 
invested by straight fib 
|I|5 tissue. In other places, devel- 
opment has pi I to the 

formation of minute 
trabecule of various fon 
¥/ containing ja< JOr- 

a ^" : " ; puscles and pre* 

their peripheral portions, superposed roundish formatioi 

97). 

The opinion formerly entertained that the tumor merelj 
tends the bone, forces the external layer outwards, ifl disputed 
by Virchow on the ground that these turn 'in 

such magnitude, that, if there is merely a die , it would 

impossible for the bony shell to continue unbroken. It is much 
more probable that a new-formation of 

place upon the outer surface from tin- periosteum, in t: - 
manner in which the apposition of fresh lav- 
bone. In the case cited, a complete destructioi : tiun of 
the maxillary wall ensued from resorption. 

In the upper jaw, also, the fibromata attain quite larg^ dimen- 
sions. Several of the tumors which I have had the opportunity 
of examining contained so many calc that the 

surfaces of sections through them communic 

* Fig. 97. — Section from the central portion of tl 

bundles of fibrous tissue include fusiform cells containing 

interlace with one another. Nests oi' ovoid cells 

there. The highly-refractive calcified portions hav 

ance and a roundish or elongated form [a). Th 

the character of young, imperfectly-develo] . ami are 

surrounded by roundish, nucleated formative cells (ft). The 

in many places, has a coarse granular appearance ; the jagged I"" 

cles are more or less minute, and notched cavities filled with amor] 

calcareous salts are brought into view here and there. M I 400 

diameters. 



SARCOMATA OF THE JAWS. 343 

ing. Dr. Friedlowski showed me a skull, from the anatomical 
collection, which presented a breach involving the facial wall of 
the antrum of the left side, a portion of the horizontal plate of 
the superior maxillary bone, and of the inferior turbinated bone. 
The second molar on the left side was inclined anteriorly, and 
the alveolus of its anterior facial root was entirely destroyed. 
The alveolar process was wanting, from the canine as far as the 
second molar. The breach in the bones extended upwards to 
the vicinity of the zygomatic arch and was bounded everywhere 
by sharp edges. The tumor which occupied the smooth-walled 
cavity corresponded in character to those above described, ac- 
cording to the statements of Dr. Friedlowski. 

Since these tumors may be enucleated, resection may be 
avoided in suitable cases. 

Sarcomata of the Jaws. — Without taking into considera- 
tion those which are developed from the alveolar process and 
have been treated of in the preceding pages, sarcomata are of 
frequent occurrence, especially in the lower jaw, in the form of 
simple, cysto-, and osteo-sarcomata. 

The cysto-sarcoraa is developed in the spongy tissue of the 
bone, which is very abundant in the lower jaw. A portion of 
this tissue undergoes complete resorption, and in its place occur 
sarcomatous masses and cyst-like cavities of various dimensions, 
some being very small while others are tolerably large (Atlas, 
Fig. 143). The larger cavities are lined with a separable, con- 
nective-tissue membrane, the internal surface of which is covered 
with a coating of small cells. Reddish, succulent proliferations 
of a roundish, tuberculated, nodulated, mulbenw-like form, pro- 
ject into these spaces which are filled with a thin, yellowish, 
yellow-brownish, or a thick, viscid, stringy, ropy fluid. 

In the case illustrated in the Atlas, Figs. 142 and 143, the 
sarcomatous mass has a quite remarkable structure. There is 
a fibrillated stroma of connective tissue; in this are imbedded 
vesicular and tubular cavities which, here and there, subdivide 
and everywhere are lined with cylindrical epithelium, the whole 
presenting the appearance of a utricular gland with many 
terminal vesicles as if detached by constriction. These adenoid 
masses inclose multifariously-sinuated cavities which attain con- 



344 NEW-FORMATIOXS. 

siderable size in consequence of the secretion of a fluid on the 
part of the colunnar epithelial cells and their proliferation. 
The adenoid structure is apparent wherever a sarcomatous 
is to be seen, and is wanting wherever a dense, firm, fibrous, 
connective substance occurs, as in the cicatricial gum corres- 
ponding to the detached teeth. This ease, therefore, may be 
termed, more appropriately, cysto-sarcoma adenoi 

The origin of the heterologous, adenoid substance is quite 
obscure. It is barely possible that it is to be referred to mani- 
fold budding outgrowths from an enamel germ. I am unac- 
quainted with the record of a similar cai 

According to the report of the case by Podraski,* the aft 
commenced in a vigorous man, thirty-three yean 
seven years previously, at which time a carious lower moll 
the left side was extracted on account of severe pain. For 
eighteen months afterwards, there was an absence <>f symptoms. 
After this period had elapsed, a tumor made it- appearai 
the gap left by the extracted tooth: this increased, howi 
quite slowly, and at the expiration of several months had at- 
tained scarcely the size of a hazelnut ; it then imparted a dis- 
tinct sensation of fluctuation and, according t<» tin- report «>f the 
surgeon who was consulted at that time, presented the appear- 
ance of a cyst, which was opened by an incision and a poriform, 
thin fluid was evacuated. Seven months later the tilled 

again with a dense mass of a pale-red color; it gave rise to no 
pain, but interfered with mastication. The tumor iras partially 
cut away, burnt and cauterized, but to no pur] tinned 

to grow without occasioning any disturbance of tl. 
tern and, finally, attained to a considerable volun, 
was performed and cicatrization ensued speedilv without the 
least disfiguration. 

The proliferations of sarcomatous masses take place in all 
directions and give rise to resorption of the corresponding por- 
tions of the alveolar processes, the alveoli and even the dental 
roots; the surface of the root becomes roughened and studded 
with delicate needle-like points; the teeth become displaced. 



* Wittelshofer's mediz. Wochenscbrift, Bpitalswitung, I 



SARCOMATA OF THE JAWS. 345 

loosened and, finally, detached. When the proliferations assume 
a direction towards the face and the tongue, portions of the 
compact bony walls undergo complete resorption, leaving the 
tumor covered merely by the distended maxillary periosteum. 

In order to obtain a definite idea respecting the extent and 
the details of the resorption, and the condition of the teeth, it 

Fig. 98.* 




is best to examine the resected jaw, after it has been stripped 
of the soft parts. Fig. 98 illustrates a segment of the jaw, pre- 
pared in this way, in which the cysto-sarcoma acquired about 
the size of an orange. The oral mucous membrane was very 
tense, swollen, and upon the lingual surface presented an open- 
ing from which oozed a stringy fluid. In the substance of the 
jaw lay a larger cyst, filled with fetid, decomposed pus, and a 
smaller one filled with a serous fluid which was tinged with 
blood. The greater portion of the alveolar process, the lingual 
and facial walls were wanting, the result of the destruction of the 
bone by the sarcomatous new-formation. 

Upon resected, macerated jaws where the newly-formed mass 
has not effected a marked destruction of the bone, the compact 
bony walls, which are involved in the resorption, present a dis- 



* Fig. 98 shows a resected, inferior maxillary arch from the left side, from 
which the soft parts have been removed. (From the clinic of Prof. Pitha.) 
View from the facial side. As the cysto-sarcoma did not involve the 
inferior, compact portion of the maxillary arch, the bone at this part 
was sawn horizontally, and obliquely upwards. The wisdom tooth (a), 
still inclosed within the dental sac and inclined towards the median line of 
the jaw and somewhat anteriorly, was the only tooth remaining. Natural 
size. 



346 



NEW -FORMATIONS. 



tended appearance and, upon their internal surfaces cor, 

ing with the cavity, are beset with delicate, pi 

c/bone which assume a fan-shaped arrangement where the teeth 

are still present. 

The cvsto-sarcomata are developed slowly and, I 
exist for many years without giving 

tions; at last resection is demanded by the patient* 

of the marked disfigurement of the face and 

with the act of mastication which th< . 

chiefly with young persoi 

There is J special occurrence to 1 

which has never been duly appi 

thorough investigation, namely, a retarded erni 

dom tooth in consequence of its obliqu r ,n " 

tevnal inclination), or a permanei :i frithlD 

the jaw, on account of its obliquity. [1 

under special circumstances, the growi 

continued irritation of the inferior maxillary w 

which gives rise to the pathological n- 

Sarcomatous proliferations may manifest th 

while the development of the tooth within the dental ■ 

progress. E. Neumann* re\ 

jaw which occurred in connection with I lm 

connective tissue of a tooth-sac. A spherical 

an apple, occupied the interior of the maxillary bon 

mass contained, besides a cyst and nun 

soft, red, spongy tissue, principally, and was h 

capsule of connective tissue: it consisted of papillar 

'excrescences supplied with wide capillary loops which N 
considered to be derived from the normal papillae thai 
from the walls of the dental sac into the gelatinous - •* the 

enamel onran. The two. somewhat stunted, 
tooth were firmly mortised into the capsule, while th< 
having four cusps and imperfectly covered with enamel, 
jected into the cyst. The tooth was located upon the I 
portion of the bony wall facing the oral cavity, directly ber 



a 






SARCOMATA OF THE JAWS. 347 

the anterior bicuspid. Its roots, directed downwards, rested 
upon the floor of the bony shell, its crown was directed up- 
wards. In this case, then, we find, in connection with a reten- 
tion-cyst of a molar, a spongy new-growth which, possibly, had 
its origin in the commencement of the growth of the roots of a 
very deeply located tooth, whereby the vascular and nervous 
trunks were subjected to an irritation. 

The simple periosteal sarcomata are located upon the surface 
of the jaw, but spread into the substance of the bone, especially 
if they are of long duration. They are composed of multifari- 
ously interlacing bundles of elongated, fusiform cells. Myeloid 
sarcomata, also, are recognized, which grow out from the medul- 
lary portion of the jaw and inclose, together with others, the 
multi-nucleated, gigantic cells which have been mentioned before 
(com p. ]). 325). 

The osteo-$areomata s regarded by Virchow as that variety of 
sarcoma which is more nearly allied to the osteomata, have their 
representatives in the ossifying epulides and. likewise, occur upon 
the jaw without t lie alveolar process. Schuh* introduces, under 
the head of secondary osteoids, a variety as having originated 
from cellular-tissue tumors, which require notice in this connec- 
tion. According to his observations, soft, painless tumors, uni- 
form to the touch and of remarkably slow growth, exist for 
several years, prior to the occurrence of ossification, in healthy 
individuals (in one case in a man with tuberculosis), at the 
middle period of life; after ossification of the greater portion 
has ensued, proliferations of new, roundish lobules of connective 
tissue sometimes take place in connection with an increased 
formative action. They arise, generally, upon the outer sur- 
face of the lower jaw ; sometimes they acquire such enormous 
dimensions that the tooth becomes displaced, loosened and de- 
tached, and the mass, rendered indistinctly lobulated and 
botryoidal by the ossified portions, extends from the chin to the 
articulation of the lower jaw, or from the nose to the mastoid 
process, and from the zygoma beyond the inferior margin of 
the body of the maxillary bone. 

* Pseudoplasmen. 



348 NEW-FORMATIOXS. 

Gelatinous Tumors (Rokitansky), Myxomata (Tirchr 
These are developed within the jaws, may acquire notable 
dimensions and are characterized, chiefly, by a predominance of 
young connective-tissue cells in an areola]- ixed 

varieties, myxoma fibrosum, enchondromatosum and c 
have been observed. The following history of a remarkable 
example of the last variety is given in detail in consequence of 
its infrequent occurrence and its malignant character. 

An extensive tumor was developed with great rapidity in the 
lower jaw, upon the left side, and wi opanied bj I 

severe pain. Resection was performed by Dr. Lewinskj, and 
the wound healed per primam inti n 

The neoplasm, consisting of several protnbe united 

together, commencing just beneath the condyloid pr the 

left side, extended as far as the canine tooth on tl. 
having a long diameter of nearly one decimetre. Onlj 
small portion of the compact cortical Bubstance of the ; 
mained, from the condyloid proceaa downwardfl and upon the 
left of the canine tooth. The thickened periosteum of the cor- 
responding portions passed immediately into the den* 
branous investment of the tumor. At the angle of the 
several protuberances, as large as a chestnut, | 
wards and inwards and, having a very much 
covering, afforded an indistinct .sense of fluctuation. The 1. 
zontal and ascending rami of the jaw were movable I 
each other. The coronoid pi itirelj concealed 

the tumor which ascended from the knobbed inferior ma _ 
the jaw to a height of seven to eight centimetr- the 

protuberances, about the size of a walnut, had ruptured inl 
nally and presented in their interior, a gelatin Id fluid 

which was tinged with blood. These cavities were lined with a 
framework of minute, intercommunicating | mimer 

smooth, reddish, soft excrescen 

The oral mucous membrane was considerably swollen. The 
crown of an upward-displaced molar tooth projected I 
the swollen gums. 

The muscles attached to the ramus of the jaw appeared a, if 
they had beea permeated by a gelatinous (sahig), reddish sub- 



CARCINOMATA OF THE JAWS. 349 

stance; the mylo-hyoid nerve presented a fusiform swelling in 
its course, from an infiltration of a similar substance. 

A section through the entire tumor, from the middle of the 
condyloid process as far as the sawed surface, showed the bone 
to have been displaced by a gray-reddish mass, in the process 
of degeneration here and there, and inclosing cavities the size 
of a lentil or pea. The osseous substance, with the exception 
of very slight portions, had disappeared. The histological ap- 
pearances are illustrated in the Atlas, Fig. 141. 

It may be remarked, further, that the muscular fasciculi in- 
serted into the ramus of the jaw, their tendinous expansions, the 
gum and the dental periosteum, but not the pulp of the molar 
tooth, were affected in a similar manner by the proliferation, 
with the exception that the small cysts (resembling those of the 
thyroid gland), together with their hyaline contents, appeared 
to be less abundant and in their stead merely agglomerations of 
nuclei were formed, for the most part. So the primitive fas- 
ciculi of the masseter muscle, where they were inserted into the 
tendinous expansion, presented, here and there, proliferations 
of oval nuclei, surrounded by layers of protoplasm, upon the in- 
terior of the sarcolemma whence the swollen bundles no longer 
displayed any transverse striation. At other points, the pro- 
liferation occurred between tendinous bundles, nerves and blood- 
vessels. 

The malignant character of this new-formation (cysto-myxoma) 
is indicated by the multifarious prolongations into the neighbor- 
ing organs, the painfulness and the rapid growth. The results 
of its histological examination, however, exclude the idea of 
a cancerous nature. 

Carcinomata. — Epithelial cancer in the oral cavity, for the 
most part, takes its origin in the gums of the upper molar teeth, 
or in the mucous membrane of the palate. The infiltration 
spreads to the dental periosteum of the corresponding tooth, as 
has been mentioned before, but does not extend to the pulp. 
The cancer finally spreads anteriorly in the body of the upper 
jaw, and the lymphatic glands, usually, are attacked at a very 
early period. 

Epithelial cancer of the borders of the maxillary bones is dis- 



350 NEW -FORMATIONS. 

tinguished from other varieties, according to C. ' K Weber,* bv 
its decided non-malignant character, and is curable bv th 
moval of all the diseased portion. 

Medullary cancer has its seat more frequently in the upper 
jaw. According to the observations of Schuh, it oi with 

elderly people most frequently in the anterior wall of t) 
jaw, in the region of the canine fossa and the infraorbital ; 
men. It forms, at first, an immovable, painless, firm tumor 
and, sometimes, takes on a rapid growth and 
boring bony tissue in two to three months. If it extends d 
wards, towards the alveolar process, the teeth 
and fall out, in which cases 1 hare, likewise, found an infilti . 
of the dental periosteum, but could never det< 
dition of the pulps. 

Schuhf met with other cases of medullary 
affection first made its appearance upon the alvi 
posite the molar teeth, and, in one ease. U] nu |- 

taneously. The teeth became detached while the till 
yet of small size and the covering of m 
quite unaffected. It was distinguished from parulis 
by the absence of pain and by the non-occurreno 
tion of the hard, bony portion, and. moreover, tl 
emitted from the sockets of the teeth, the simull 
of both sides in one case and the marked each* 
indicated a malignant formation. ,f t | 10 | m , 

symptoms was succeeded by death, in consequ 
current affection of the internal organs, while the tumor of the 
jaw had not acquired notable dimei 

Medullary cancer may be confounded with e] I the 

surest means of discrimination is afforded bv a v. 
examination of an excised portion. 

GroheJ describes a melanot r of the intermaxilla 

bone which originated in the dental sacs of the i, 
boy hve years of age. All the incisor teeth were wanting, with 
the exception of the left lateral, and the erupti 
only imperfectly effected. Grohe regards the d< 



Op- cit. f Pseudoplasmen. J y irc i. 



ANTRUM. 351 

permanent incisors as the starting-point of the tumor and states, 
as his opinion, that the development of the former began at a 
very early period and was arrested prior to the formation of 
the dental capsules. The dental sac of the lateral permanent 
incisor on the left side was found, but it contained no trace of 
the dental tissues; it was located directly behind the milk tooth. 
In the place of the lateral permanent incisor on the right side, 
a bean-sized, melanotic mass was found, which was united an- 
teriorly to the milk teeth, posteriorly and upon either side, to 
the compact bony tissue; no remains of the permanent tooth 
were discovered. Finally, the localities of the two central per- 
manent incisors, no trace of which was found, were occupied 
by the very large new-formed mass. C. 0. Weber* recorded 
four cases of melanotic cancer in this locality, and states that 
the affection often spreads from the gums of the incisors to the 
alveolar border and to the body of the jaw. 

Fibrous <-<>ncer, extending from the gums, was not met with by 
Schuh; in the upper jaw it originated either at a point corres- 
ponding to the anterior wall of the antrum, or in the middle 
portion at the line of junction of the alveolar processes. On 
the lower jaw it usually has its origin in the interior of the bony 
tissue; at first it is tolerably circumscribed and is likely to be 
confounded with fibroma or epulis. Frequently, the pain attend- 
ing it is very slight, indeed may be wanting entirely, even under 
pressure, whereby its resemblance to epulis is all the more 
marked ; but the glands become swollen from infiltration at a 
very early period, and the patient always lias a cachectic appear- 
ance. The combination of the fibrous and medullary forms is 
not an uncommon occurrence. 

Gelatinous cancer, especially in the form of cystoid-gelatinous 
tumors of the upper jaw, observed by Rokitansky, and osteo- 
carcinomata, with a new-formation of a radiating or alveolated 
bony tissue or of a compact bony shell inclosing the soft, can- 
cerous mass, are of very rare occurrence. 

Antrum. — Cysts of the antrum are met with, frequently, and 
are of special interest to the dentist in a clinical point of view, 

* Op. cit. 



352 NEW -FORMATIONS. 

when they are developed upon the floor of the cavity, in the 
mucous membrane which, together with the subjacent periosteal 
layer, is in immediate relation with the roots of one or another 
molar or of the second bicuspid. They are liable t< le to 

a fistula of the antrum when they are accompanied bj an ini 
mation of the dental periosteum of the corresponding teeth, which 
necessitates a removal of the latter. 

Luschka* made a special study of tl ind found 

that, in some cases, they occur Bingly, and in others, :i nun 
are developed, some of which present broad, basal attacl 
and others project into the cavity, pushing the mucous m 
brane before them, and appear to be pediculatnd. :ller 

cysts, usually, contain a quite I mass resembling boiled 

sago; these masses, varying in Bize up t<. that of a hazelnut, 
inclose a yellowish, case<>u< matter, befl ;ht-colored fluid. 

Frequently, also, he found the contents resembling ine 
mucus, in which cases the eye generally clou 

appearance. 

' From his observations, Luschka is inclined I 
that by far the greater number of the < the antrum 1 

their origin in a glandular dogenera ti- 
the branching utricular mucous glands in adult-, lie met with 
cyst-like expansions, here and there, both of the principal t 
and ultimate follicles. 

In about sixty examinations, post morf thka met 

the so-called poh/pi of the m« strum in 

five cases at least. According to him. these polypi are els I 
or pyriform, and attached by means of their nan un- 

ties. In other cases, they have a flattened, lobulated form, and 
are attached by their broad extremities. Usually, the outer 
surfaces are smooth and seldom, at least to the naked eye. | 
sent an indented or foraminated appearance. Th 
by him varied from one-half to two centimetres in length. 

The favorite seat of the polypi of the antrum is upon its in- 
ternal wall, where they may completely block up the a: 
of communication with the middle meatus, and hei 



Virchow'a Archiv. 1 



ANTRUM. 353 

to accumulations of mucus. In most cases, only a single poly- 
pus was found. In one case, he found six, which, together with 
a number of cysts and an abundance of tough mucus, entirely 
filled the cavity. The parenchyma of the polypi appeared to 
him to be a lax, vascularized, connective tissue, containing an 
abundance of cell-nuclei. He has, as yet, been unable to detect 
glands of any sort in them. 

These polypi occasion no inconvenience so long as their size 
does not exceed certain limits;* if they continue to increase, 
they distend the walls of the cavity and occasion attenuation 
and resorption of the latter. In still more advanced stages, 
they give rise to a feeling of distention and weight on the cheek 
of the corresponding side; hemorrhages occur from the nose, 
and a discharge of a thin, mucilaginous, later sanious and foul- 
smelling fluid. After the cavity is filled by the polypi, the 
tumor increases in size and the pain becomes more severe in 
consequence of the distention. Most frequently, the nasal wall 
of the antrum is perforated between the second and third tur- 
binated bones, or the polypus enters the nasal cavity and is de- 
veloped therein, always, however, towards the posterior nares. 
Sometimes perforation takes place in the hard palate; a third 
location for the same process is the anterior wall of the upper 
jaw, and a fourth, the orbit, into which the polypus presses, 
either through its inferior wall or through the spheno-maxillary 
fissure or the nasal fossa along the pterygopalatine canal, or 
through the spheno-palatine foramen. The vision becomes af- 
fected in consequence of pressure upon the bulbs and the optic 
nerves. Finally, the polypus extends through the nasal cavity 
into the posterior nares and the pharynx. 

Passing over other tumors in regard to which it is doubtful 
whether or not they are growths which originate in the antrum 
rather than in other parts, it remains to be noticed that entozoa 
are said to have been found in these cavities ;f these may possi- 
bly have been the larvse of flies. 



* Adelmann, Krankhafte Zustande der Oberkieferhohle, Dorpat, 1844. 
f Benj. Bell, 1787, and Ludw. Frank, 1815. 

23 



354 ANOMALIES OF THE SECRETIONS. 



VI. ANOMALIES OF THE SECRETIONS. 

The teeth are bathed constantly with a fluid which is fur- 
nished by the salivary and mucous glands that empty into the 
oral cavity. The secretion of the three pairs of salivary 
glands, the parotid, submaxillary, and sublingual, amounts to 
about fifteen hundred grammes in twenty-four hours, according 
to the measurements of Bidder and C. Schmidt, of Dorpat. 

The saliva varies in character in the different salivary glands. 
Hoppe-Seylei* describes the secretion of the parotid in man 
and animals as a fluid which is always clear, limpid, and watery, 
without the slightest viscidity, has an alkaline reaction and, 
when boiled or exposed to the air at the ordinary temperature, 
is rendered turbid by the precipitation of carbonate of lime. 
The inorganic matter, according to the results of most anal; 
amounts to scarcely 0.5 per cent. The fluid secreted by the 
submaxillary glands is colorless, gelatinous, viscid, and thready, 
and has a faint alkaline reaction ; it throws down no dej 
when exposed to heat or allowed to stand in the air, but effer- 
vesces slightly on the addition of acids. The saliva of the sub- 
lingual is still more tenacious and viscid than that of the submax- 
illary glands, and also has an alkaline reaction. The name/ 
line has been given to the mucous or albuminoid matter which 
has not yet been sufficiently investigated. From these results 
obtained by Hoppe-Seyler, it appears that the secretion of the 
submaxillary, but more particularly that of the sublingual gland, 
contains mucin and in this respect, then, resembles the secre- 
tion of the mucous glands. 

The mucous glands of the oral cavity, which claim notice in 
this connection, are the marginal glands of the tongue, namely, 
those of constant occurrence upon either side of the apex and at 
the root, and those occasionally met with at the middle: further, 
the large labial glands, the less numerous buccal glands, and 
those of the hard and soft palate. 

The mucus is a viscid, sometimes clear and colorless, and at 

* Handbuch der physiol. und path, chemischen Analyse, 3. Aui, 1S70. 



MIXED SALIVA. 355 

others, somewhat turbid secretion, and generally has an alkaline 
reaction. 

Moreover, there exudes from every portion of the mucous 
membrane where there are no glands, and even from the gums, 
a fluid containing the effete, flattened, epithelial cells, which are 
replaced by younger cells. There is a continual process of decay 
and repair in the oral cavity. 

The mixed saliva of the mouth is a compound of saliva and 
mucus. According to Hoppe-Seyler, the saliva which escapes 
from the mouth, when it is kept open and no attempt is made to 
swallow, usually, and always after eating, has an alkaline reac- 
tion; after prolonged fasting, however, and particularly after 
continued talking, it may become acid. 

Sulphocyanide of potassium is found in the mixed saliva and 
is peculiar to the latter, having never been detected in any 
other part of the organism. Hoppe-Seyler states that in man 
the mixed saliva very frequently contains sulphocyanic acid, 
while it cannot be found in either of the secretions which com- 
pose the saliva, and adds, this acid, therefore, undoubtedly is a 
product of decomposition, and is formed primarily within the 
oral cavity, since it is not usually present after eating and, 
with some individuals, is never found, especially with those who 
have sound teeth, though even with such persons it is frequently 
formed in the saliva, when the latter is exposed to the air at 
the temperature of the blood. According to these statements, 
this acid has a pathological importance with reference to the 
teeth. Schonbein detected usually, but not always, a nitrous 
acid salt. 

Wright, in his familiar monograph,* laid the foundation of a 
pathology of the saliva. The conclusions drawn by him, ob- 
viously with reference to the mixed saliva and requiring revi- 
sion, certainly, in many respects and more extended investiga- 
tions, have a considerable degree of interest in connection with 
our present subject. He says, the acidity of the saliva in dif- 
ferent diseases is due to the presence of divers acids. Lactic 
acid is found in gout, rheumatism, intermittent fever, diabetes, 

* On the Physiology and Pathology of the Saliva, 1842-44. 



356 ANOMALIES OF THE SECRETIONS. 

gastro-enteritis; acetic acid with aphthae, scrofula, scorbutus, 
variola, indigestion, and after the use of acid wines ; hydro- 
chloric acid in connection with simple gastric disturbances ; uric 
acid in gout, and oxalic acid with digestive derangements. 
Alkalinity of the saliva occurs: a, in consequence of the pres- 
ence of an excess of soda. It is considered to imply, patho- 
logically, general or local disturbances of the nerves. The 
local affections of the nerves comprise chiefly facial neuralgia 
and odontalgia, dependent upon denudation of the pulp without 
inflammation of the periosteum of the root and the adjacent 
tissues. The alkalinity, frequently, is an important aid in diag- 
nosis, inasmuch as the purely nervous facial pain is accompanied 
almost always, by an alkaline, and the rheumatic pain by an 
acid saliva; b, alkaline saliva, in consequence of the presence 
of ammonia, is of quite rare occurrence, and is met with in 
severe catarrhal affections, putrid fever, scorbutus, and purpura 
hemorrhagica. A calciferous saliva, containing carbonate of 
lime, gives rise to the formation of tartar, salivary calculi, and 
ranula. The latter condition, by no means of rare occurrence, 
is accompanied by dyspeptic symptoms. 

According to the statements of Ktihne,* urea is the only ab- 
normal substance that has been identified with certainty in the 
(pure) saliva; this is found in Bright's disease and, also, in the 
secretion from the submaxillary glands of animals, after the 
ligature of the ureters. The sugar found in the oral cavity of 
persons affected with diabetes, he says, is never a product of 
true saliva, but, probably, of the bronchial mucus, since it can- 
not be detected except in cases where the oral cavity is not 
properly cleansed or after hard coughing. Further investiga- 
tions, lie adds, are necessary in order to determine whether the 
characteristic, often very noticeable odor, emitted from the 
mouths of diabetic persons, is dependent upon an ingredient of 
the saliva. 

In febrile affections, as is well known, the salivary secretion 
is diminished, the mouth is dry, and the epithelium accumula 
since it is not removed by the saliva. 

* Phvsioloir. Chemie. 1SCS. 



DEPOSITS UPON THE TEETH. 357 

In catarrhal inflammation of the oral mucous membrane and, 
especially, in mercurial salivation, as much as one per cent, of 
inorganic salts has been found in the saliva of the oral cavity. 

The normally thin, slightly turbicl, pellucid, odorless coating 
upon the teeth, is a secretion of the gums mixed with the oral 
saliva, and accumulates particularly in the intervals between 
the teeth. In the recent condition, this coating is neutral and, 
exceptionally, it is slightly acid. In man, at least, it is the 
frequent seat of living organisms, concerning the nature of 
which there has been much discussion.* 

When the coating forms a pultaceous, unctuous, cloudy mass 
having, occasionally, a feculent odor, it consists, principally,' of 
a uniformly fine-granular mass which formerly was considered 
to be organic detritus, but at present is regarded as so-called ma- 
trix of leptothrix and sometimes is distinguished as micrococ- 
cus. The grains are disposed upon the outer surface of the 
exfoliated epithelial cells, but, in consequence of their minute- 
ness and rapid multiplication, their cell-nature and division are 
scarcely recognizable with the optical appliances in use at the 
present day. The epithelial cell becomes masked by the in- 

* Leeuwenhock, who discovered these (1695), descrihes them us lines of 
varying length and uniform thickness, bent in some places, straight in 
others, and irregularly disposed. He conjectured that these bodies were 
animals, from the fact that he had met with them alive in water; he could, 
however, detect no movement in those of the coating of the teeth. Biihl- 
mann (1840) demonstrated their property of withstanding the action of 
concentrated sulphuric and nitric acids and caustic alkalies. For some 
time, in consequence of the uncertainty regarding their nature, they were 
termed Biihlmann's fibres. Henle was the first to suggest the vegetable 
nature of these filaments, while, on the other hand, Ficinus (1846) advo- 
cated their animal nature, and designated the animated organisms as denti- 
colae, and connected them with caries of the teeth. Eobin (1847) placed 
them in the family Leptotrichese of Kiitzing, and applied to them the name 
Leptothrix buccalis which has generally been accepted. Robin, conse- 
quently, ranked leptothrix with the algae, while, in modern mycology, they 
are classed with the fungi. Hallier (1860) is inclined to have leptothrix, 
as a generic term, banished from mycology, considering this fungus to be 
merely a vegetation form of different lower fungi which he denominates 
leptothrix series. Hallier goes still further and states that leptothrix buc- 
calis is merely a form of development of the ordinary mould fungus, peni- 



358 ANOMALIES OF THE SECRETIONS. 

crease of the granular formations, and to the latter, attach 
themselves, in the course of time, bundles of tolerably long, 
usually interlacing, uniformly thick filaments ; these frequently 
are short, rod-shaped, and commonly are designated by the 
term Bacteria. These vary in length and thickness, usually are 
isolated, less frequently occur in chain-like rows, and manifest 
periodical oscillatory movements. Leber and Rottenstein* ob- 
tained a violet color from the leptothrix grains and filaments, 
by treatment with iodine and acids, a reaction which ensues 
much more readily, as I have also convinced myself, if dilute 
hydrochloric acid be employed, after the fungus has been 
treated with an aqueous or alcoholic solution of iodine ; a mix- 
ture of glycerine and tincture of iodine, I have also found to be 
advantageous. The reaction, as Leber and Rottenstein have 
shown, displays the transverse markings of the filaments in a 
beautiful manner. The interior portions are colored, and the 
septa of the filaments remain without being colored. The same 
reaction ensues, as is self-evident, with the matrix and threads 
of leptothrix in the coating of the tongue. 

The extremely delicate, coiled filaments (Spirillum), which 
occur in fewer numbers in the coating upon the teeth and were 
included by Ficinus in his Denticola?, are regarded by several 
mycologists as swarm-spores of leptothrix. The abundant, ani- 
mated grains, according to the opinion of Hallier, are likewise 
swarm-spores which arrange themselves in the form of continuous 
chains. Now and then a mycelium is met witli identical (isomorph) 
with that found in the fungus of aphthae [Oidium albicans]. 

Leptothrix is found very frequently in the oral mucous mem- 
brane. Robinf cites H. I. Bowditch, who found that out of 
forty-nine individuals taken from all classes of the community, 
not one of whom exhibited a diseased mouth, forty-seven pre- 
sented vegetable or animal parasites in the intervals between 
the teeth or in the localities corresponding with the junction of 
the latter with the gums. Bowditch considered them to be 
merely the result of a want of cleanliness. 



* Ueber Caries der Zahne, 186 7. 

f Histoire Naturelle des VegeUux Parasites. 18Cv3, p Sol. 



DEPOSITS UPON THE TEETH. 359 

Individuals with swollen gums, pregnant women, or those 
who are afflicted frequently with dyspepsia, with inflammation 
of the tonsils and mucous membrane of the fauces, or with mer- 
curialismus, scrofulosis, scorbutus, or who live in a confined 
atmosphere and are especially exposed to agencies which pro- 
duce an irritation of the gums, are very liable to be affected 
with leptothrix, notwithstanding an abundant secretion, and 
even with the utmost cleanliness. 

The colored, firmly-adherent deposit on the teeth assumes a 
decided green, gray-green, gray-brownish, gray-yellowish, or 
brown color. The green deposit occurs, not merely in advanced 
age, but also upon the teeth of young persons, both upon nor- 
mally-formed and abnormal teeth, whether they present accu- 
mulations of tartar or not, and whether they are affected with, 
or do not show the least evidence of caries. 

It is most conspicuous upon the labial surfaces of the front 
teeth of the upper jaw, in the form of a superficial discoloration 
of the enamel, which follows the lunated margin of the gum 
and acquires its greatest intensity at a certain distance from the 
gingival margin and towards the incisive edges, coronal eminences 
and cusps of the teeth. The discolored portions present spots 
where the tinge is more or less intensified. The latter, usually, 
are more evident in the depressions produced by erosion of the 
teeth. 

The thin deposit, which is distributed without uniformity, 
cannot be washed off with water nor wiped off, but must be 
scraped away with a sharp knife, when the enamel will be found 
bright and intact. 

Examined with reflected light, the deposit is found to be a 
granular mass. It is more advantageous to make use of the 
green deposit, after it has been scraped away, for investigation, 
or still better, the membrane of the enamel [Nasmyth's] which 
may be detached by means of dilute hydrochloric acid; by these 
means, it may readily be demonstrated that the deposit is a 
green, green-yellowish, uniformly minutely granular mass which 
is morphologically identical with the matrix of leptothrix. 

If the membrane of the enamel is preserved in glycerine, the 



360 ANOMALIES OF THE SECRETIONS. 

green not unfrequently disappears in a few days, leaving a dirty 
yellow, yellow-brownish color. 

1 have never observed a penetration of the green, granular 
mass into the peripheral enamel layer, though I have met with 
systems of enamel prisms, containing deposits of pigment, which 
have acquired a greenish color in their cortical layers, a condi- 
tion which may be explained by the penetration of the green 
coloring matter. 

The dark-broivn deposit, as it occurs with habitual smokers, is 
observed upon the lingual surfaces of the teeth, especially of the 
upper molars; almost always it is very thin, may be scratched 
off, accumulates, particularly, in the depressions of the enamel 
and, ultimately, forms a sooty covering over the entire lingual 
surfaces, from the masticating surfaces to the borders of the 
gums which, usually, are considerably retracted, especially oppo- 
site the lingual roots of the upper molars. 

If we examine the surfaces of transverse sections through the 
necks of teeth presenting the sooty coating from the use of to- 
bacco, the dentinal layer nearest the deposit presents a grayish 
discoloration, giving an appearance as if the adjoining dentine 
had become involved in the staining process, so that it might be 
supposed that the coloring matter had penetrated to the dentine. 
This, however, is not the fact. If a portion of the sooty coating 
be scraped off, the dark discoloration of the corresponding por- 
tion of the dentine disappears, showing that it was due to the 
transparency of the dentine. This appearance becomes more 
conspicuous in a cross-section of a senile tooth with a sooty 
coating and horny translucent dentine. 

If the scrapings of the sooty coating are treated with dilute 
hydrochloric acid, a few bubbles of gas will be set free and 
there is left a dark-brown, laminated mass, consisting of amor- 
phous, brittle plates with an angular fracture, and containing 
neither matrix nor filaments of leptothrix. 

A peculiar deposit with a metallic lustre is met with especially 
upon the teeth of cattle. If scrapings of this are treated with 
hydrochloric acid, the morphological elements present very thin 
lamellae of cornified epithelium which has acquired a yellow- 
color. The metallic lustre, therefore, is a phenomenon of inter- 



ODONTOLITHUS — TARTAR. 361 

ference occasioned . by the superposition of the uncommonly 
thin, cemented lamellae. 

The formation of the adherent deposit upon the teeth may 
readily be explained. Since the gums are attached to the dental 
necks and the extremities of the papillae upon the gingival 
borders project slightly, accumulations of the secretion of the 
gums are the more likely to take place in these localities. This 
secretion flows downwards upon the upper teeth and accumulates 
especially in the depressions and. grooves of the enamel surface. 
In consequence of the frequent occurrence of leptothrix in the 
oral cavity of man, this epiphyte finds a lodgment in the viscid 
coating containing effete epithelium. The latter, in conjunction 
with the proliferating leptothrix, becomes saturated with the 
constantly secreted saliva, the calcareous salts of which are 
precipitated in the minutely-porous substratum. In this way, 
there is formed a cemented mass which cannot be removed from 
the surface of the enamel except with the aid of sharp instru- 
ments. With regard to the deposit upon the teeth of cattle, 
and to the brown deposit produced by tobacco-smoking, it is 
obvious that leptothrix is not required in their formation. 

Several varieties of odontolithus, tartar are distinguished, the 
most common of which are the white porous, the gray-brownish, 
dark-brown with black superficial layers, now and then like 
ebony, and the dirty green. 

The white tartar, which occasionally has a tinge of gray or 
yellow upon its outer surface and in cross-section presents a 
chalky whiteness, occurs upon the facial aspect of the dental 
necks and in greatest abundance upon the bicuspids and molars, 
particularly upon those of the upper jaw; its exposed, rounded, 
outer surface is polished more or less by friction with the mucous 
membrane. Its formation begins at the border of the gum and, 
sometimes, it acquires dimensions sufficient to envelop completely 
the crowns and their masticating surfaces. If the roots of the 
teeth are deprived of their protective coverings in consequence 
of a continued accumulation of tartar and chronic suppuration 
of the gums, periosteum of the roots and alveoli, the tartar then 
extends to the apices of the roots and may spread even beyond 
them. As it is disposed about the separate teeth, and the latter 



362 ANOMALIES OF THE SECRETIONS. 

admit of a certain degree of movement during mastication, it is 
obvious that adjacent masses of tartar become smooth from 
friction with each other. The lingual surfaces of tartar are 
rendered smooth by the movements of the tongue. Fig. 128 in 
the Atlas illustrates a colossal mass of tartar inclosing four 
teeth, which was reported by Heider.* Strasky, of Lemberg, 
removed this deposit from the mouth of a Polish Jewess who 
went to Lemberg for the purpose of being operated upon for the 
removal of a supposed tumor of the bone, for which she had been 
treated at home, without success, with iodine and mercurial 
preparations. 

The explanation of the fact that tartar is formed in greater 
abundance upon the facial surfaces of the upper bicuspids and 
molars, is to be sought in the local relations, in the fact that 
Stenon's duct empties directly opposite the second upper bicus- 
pid. The saliva washes over the above-named teeth in great 
abundance and is rapidly removed from their lingual surfaces 
by the movements of the tongue, while upon their facial surfaces, 
in consequence of the contact of the cheeks with the teeth, com- 
paratively less is removed. 

Large accumulations of tartar are formed upon those teeth 
which are deprived of their antagonists, or upon painful teeth 
which compel the patient to abstain from using the corresponding 
side in chewing and biting, and to neglect proper cleanlin 
In either case, abrasion of the forming tartar is prevented. 

The lingual and facial surfaces of the necks of the lower in- 
cisors, likewise, are frequently the seat of the yellowish-white, 
porous tartar. The saliva from the submaxillary and sublingual 
glands collects upon the floor of the oral cavity and gives rise to 
an increased deposit which sometimes spreads nearly to the 
apices of the dental roots. 

Castle asserts that the tartar sometimes is deposited even in 
the foramen which serves for the transmission of the dental 
nerves, and occasions severe neuralgias in the branches of the 
fifth pair; that it is deposited, also, upon artificial teeth, upon 

* Mittheilungen des Centralvereines deutscher Zahnarzte. 18 



ODONTOLITHUS — TARTAR. 363 

the gold and silver or gutta-percha in which the artificial teeth 
are set, but never within or upon the alveolar processes. 

Polished surfaces of sections of the larger deposits of tartar 
display concentric laminae corresponding in their direction with 
the curvature of the outer surfaces. Thin slices are not in- 
structive since they present merely amorphous, opaque masses 
which, for the most part, afford a considerable amount of organic 
residue when treated with acids. I have succeeded better in 
delineating the details of the laminations, by making sections of 
fragments of the tartar by means of a sharp knife and treating 
them with heated acetic acid. When the calcareous salts have 
been removed, coherent systems of mortised, delicate, sharply- 
defined layers, separated from one another by intervals measuring 
scarcely 0.001 millimetre, are brought into view. Roundish 
disks of various diameters form the foci ; around the whole or 
portions of these, the layers are disposed as in the agate, pre- 
senting a resemblance to those displayed in very thin sections 
of urinary calculi of uric acid. Here and there, laminated or 
separate, effete epithelial cells, and the granular matrix or 
numerous filaments of leptothrix, are met with. If a number 
of thin slices of tartar are treated with very dilute hydrochloric 
acid for the purpose of studying the organic residuum, in ad- 
dition to occasional vegetable remains, thallus-threads of oidium 
are found, occasionally, in not inconsiderable numbers (Atlas, 
Fig. 129), forming free projections upon the corroded portions. 

The gray-brown or dark-brown tartar is considerably harder 
than the preceding, accumulates in smaller masses and more 
slowly and attaches itself chiefly to the lingual surfaces of the 
necks of the lower incisors ; it occurs often upon the upper in- 
cisors, canines, and bicuspids, less frequently upon the lingual 
surfaces of the molars and still more rarely upon their buccal 
surfaces. 

Surfaces of sections of this form of tartar display irregularly 
wavy laminae, presenting various shades of dirty-brown, gray 
and yellow. The laminae vary in thickness, for the most part, 
present imperceptible transitions from one into another and, 
here and there, form a distinctly stratified system. Since, in 
many places, the dark and bright layers are arranged in close 



364 ANOMALIES OF THE SECRETIONS. 

proximity, an appearance is presented, bearing a strong resem- 
blance to the white porous tartar (Atlas, Fig. 130). 

Thin sections or slices, from which the calcareous salts have 
been removed by means of dilute hydrochloric or heated acetic 
acid, do not present any lamellae of effete incrusted epithelium, 
but contain an abundant homogeneous mass of minutely granu- 
lar leptothrix. Quite numerous leptothrix filaments, likewise, 
occur in tufts here and there ; numbers of isolated, so-called 
bacteria, also, may readily be demonstrated by means of tritura- 
tion. The brown color, in many layers, arises partly from dark 
and light brown, free granules, and in part, also, it is due to the 
general brownish tinge of the molecular mass. Sometimes, a 
color shading into greenish is met with. 

The gray -green tartar is very hard and forms a ring around 
the neck of the tooth, generally several millimetres broad ; quite 
often it is covered by the gums and has a more or less nodulated 
outer surface; it is thickest in the portion adjacent to the 
gingival border, and becomes attenuated both in the direction of 
the root and towards the crown. 

Hydrochloric acid slowly extracts its calcareous salts, leav- 
ing a comparatively large amount of greenish leptothrix matrix, 
together with numerous filaments. Brown, granular agglomera- 
tions are imbedded here and there. 

Tartar is very common on the teeth of old animals. In the 
horse, white tartar is distinguished by its containing an un- 
usually large amount of carbonate of lime, which is indicated by 
the very active effervescence produced on the addition of acids. 
In the dog, the green tartar exhibits a comparatively large 
amount of organic matter. The tartar with a metallic lustre, 
which is found on the teeth of cattle, is of especial interest, from 
the fact that in this the mass of leptothrix and the necrotic epi- 
thelial layers are sharply distinguished from each other. Even 
with the naked eye, a number of fine pores may be seen upon 
the surface of this form of tartar ; with the aid of a lens, thin, 
decalcified slices display a network of canals which prove to be 
cavities filled with a mass of leptothrix. Between these cavities 
lie the multifarious, brittle, yellow lamellae of cornified epithe- 
lium. 



ODONTOLITHUS — TARTAR. 365 

Mandl* has advanced the view that tartar is composed of a 
cluster of vibriones which are encased in a coating of lime. 
Though it is true that parasitic organisms participate in the 
formation of tartar, nevertheless the view of Mandl is untenable, 
according to the ideas of the present day, since the supposed 
vibrios are constituent portions of leptothrix and possess no cal- 
careous coats. 

The amount of calcareous salts, the relative proportion of 
carbonate and phosphate of lime,, the quantity of organic matter, 
the quantity of leptothrix buccalis distributed in the calcified 
portions and the occasionally included particles of food present 
many variations in the different kinds of tartar. Generally 
speaking, it is observed that tartar contains the same constitu- 
ents as salivary calculi with the exception that it has a greater 
amount of phosphate of lime than the latter. Berzelius, as is 
well known, also demonstrated the existence of an albuminoid 
substance in tartar, called ptyaline, a fact of importance inas- 
much as the participation of the saliva in the formation of tartar 
is vindicated even upon chemical grounds. 

Two elements are to be discriminated in connection with the 
formation of tartar, in the first place, the organic cement and 
in the second place, the inorganic salts. The former is fur- 
nished by the mucus and epithelium from the gums, by the 
mucin-holding substance of the mixed saliva, and by the lepto- 
thrix buccalis which proliferates in the degenerating substances. 
It cannot be asserted that the latter is an essential ingredient 
of tartar ; it gives firmness, however, to the organic cement and 
increases the consistence of the green and brown tartar. 

The calcareous salts are deposited chiefly from the saliva. 
If the latter contains an unusually large amount of such salts 
and, especially, if the salivary secretion is augmented, the tartar 
is deposited with comparatively greater rapidity. Hoppe- 
Seyler asserts that, in cases of iodine and mercurial salivation, 
the saliva contains an abundant admixture of the secretion pro- 
duced by the catarrhal inflammation of the mouth and throat 
and, hence, on being boiled with the addition of a little acid, it 

* Comptes rendus de l'Acad. des Sciences de Paris, t. 17. 



ANOMALIES OF THE SECRETIONS. 

usually affords an abundant coagulum, particularly in cases of 
mercurial salivation ; moreover, as has already been observed, it 
contains nearly one per cent, of inorganic salts, while normal 
saliva contains a much smaller amount. 

The concrement becomes foraminated by the constant action 
of the saliva upon the surface of the tartar ; indentations and 
fissures are formed (Atlas, Fig. 128), which afford a favorable 
nidus for the proliferation of leptothrix buccalis. These cir- 
cumstances explain the occurrence of sharply defined channels 
filled with a mass of leptothrix, which are so conspicuous in the 
tartar of the teeth of cattle. 

Fox* stated explicitly that, with the exception of caries, noth- 
ing is so pernicious to the healthy condition of the mouth and 
the durability of the teeth as the accumulation of tartar. 
Hunter, and previous to him, the French dentists Faucbard and 
Bourdet, were quite well aware of the injurious effects of tartar. 
These comprise the production of a catarrhal inflammation of 
the gums, the loosening of the adhesion of the latter to the 
necks of the teeth ; the tenacious mucus collects in the pockets 
formed by the gums and forms an incrustation upon the necks 
of the teeth and a superficial ulceration takes place upon the 
borders of the gums. Not infrequently the irritated gums be- 
come swollen and superficial hemorrhages ensue. If the gum 
is involved where it becomes continuous with the root-membrane, 
a sensitiveness of the tooth is produced. The accumulated 
purulent mucus undergoes decomposition and emits a fetid odor 
from the mouth; it undermines the contiguous alveolar wall in 
which it induces a resorption; then the tartar is deposited 
directly upon the cement of the root, without affecting the den- 
tal substances in the least, and it is not an uncommon occur- 
rence for the corresponding root to be incrusted as far as its 
apex in consequence of which, the tooth, especially if it has but 
a single root, becomes loosened and detached. Frequently, 
however, the sensitiveness becomes so marked in consequence 
of the affection of the periosteum of the root, that patients 
decide upon extraction even before the tooth has become loose. 

* Nat. Hist, of Human Teeth, p. 9-5. 



CARIES OF THE TEETH. 367 

The tartar, therefore, does not injure the teeth directly, but 
merely in an indirect manner through the irritation produced by 
its more or less rough, tuberculated surface upon the gum, 
chiefly within the pockets formed by the latter. If it has sharp 
edges projecting over the gum, as is wont to be the case, par- 
ticularly upon the lingual surfaces of the lower incisors, or if 
one or another portion of the tartar break away, still further 
injurious effects are produced. Large masses of tartar do not 
occasion more serious effects, since their outer surfaces become 
smooth. 

It is impossible as yet to explain, in every case, the deposit 
of tartar upon the teeth of many persons, in spite of the utmost 
cleanliness. 

Calciferous saliva and catarrh (comp. inflammations of the 
gums) favor the formation of tartar, as also does advanced age, 
principally because at this period the secretions are diminished 
in quantity and the regeneration of the epithelium of the gums 
takes place more slowly. 

Caries of the Teeth. — It was quite natural to transfer to 
the teeth the signification implied in the expression " caries 
(Beinfrass) of bone," indeed the fundamental phenomena, 
namely, the destruction of the hard tissues, offered a striking 
analogy. In their development, however, the two processes by 
no means present such an identity. Caries of the bone, as is 
well known, is an inflammatory process (ostitis) which originates 
in the soft parts of the bone and erodes its hard tissues. This 
is not the case with the carious process in the teeth, which com- 
mences in the hard tissues and spreads to the vascularized and 
nervous dental pulp. Upon close investigation, the latter pro- 
cess is found to be so entirely distinct from the former that 
the attempt has repeatedly been made to expunge altogether 
from the nomenclature of diseases of the teeth, the expression 
caries of the teeth, and Klenke has proposed to substitute the 
general term "decay (Verderbniss) of the teeth." This propo- 
sition, however, did not meet with very general acceptance, and 
it must be acknowledged that, on the one hand, nothing is 
gained by the introduction of so vague an expression, and on 
the other hand, it would be almost an impossibility to give up a 



368 ANOMALIES OF THE SECRETIONS. 

term -which has become naturalized in dentistry and, indeed, 
even with the general public. 

There is by no means a unanimity of opinion in regard to 
the category of diseases under which caries of the teeth is to be 
classed. The ground which we have taken is indicated by the 
fact that caries is introduced under the head of anomalies of the 
secretions, or, in other words, it is considered to be the result 
of abnormal secretion. The reasons for this view will appear 
in the following pages. 

The importance of the process in this very frequent affection, 
the treatment of which forms the largest part of tbe practice of 
the dentist, leads me to enter minutely into the history of caries. 
The latter, moreover, is instructive, inasmuch as it indicates 
the marked proneness of the human mind, from its natural ten- 
dency to investigate the causal connection of phenomena, to 
wander in the mazes of hypotheses, when, in the absence 
of sufficient preliminary knowledge, it is prevented from pene- 
trating the realms of truth. Notwithstanding the fact that our 
knowledge is advancing, unquestionably, with the continual addi- 
tions to the auxiliary means at our command for carrying on the 
work, it must, however, be acknowledged that a theory with 
regard to caries, with a thoroughly scientific basis in all its de- 
tails, is still wanting. 

Hippocrates and his pupils, as is well known, were humoral 
pathologists, and hence they referred caries to the bad condition 
of the humors, a. view which was maintained by most physicians 
for more than a thousand years and, even at the present day, 
is upheld by the traditions of the common people. Imperfect 
observation and, perhaps, intentional deception, gave birth to 
the worm-hypothesis which furnished a decidedly more concrete 
idea of the genesis of caries. Various means were employed to 
destroy the intruders. Fauchard (1728) took a great deal of 
pains in order to discover the worms supposed to be the most 
common cause of toothaches, both in carious teeth and in tartar: 
he never succeeded in finding any. 

Fauchard distinguished several forms of caries: a scorbutic, 
variolous, scrofulous, a moist or putrid and a dry, a superficial, 
of little consequence, and a deep form which gave rise to severe 



HISTORY OF CARIES OF THE TEETH. 369 

pain. He assumed an internal and an external cause for 
caries, as he did for all diseases of the teeth. The former, he 
states, acts upon the roots, both upon their outer and inner sur- 
faces, meaning by the latter, the root-canal, and also upon the 
internal surface of the dental cavity ; caries, which is induced 
by internal causes, he continues, is recognized with considera- 
ble difficulty, especially when the roots or the necks of the 
teeth, merely, are attacked, since it is concealed from view by the 
gums and the dental sockets ; caries, depending upon external 
causes, attacks the outer portion of the tooth, i. e., the enamel, 
sometimes the neck, and at others the roots ; the internal causes 
are referable, generally, to the quantity or quality of faulty, 
acrid or corrosive lymph. 

Bourdet* maintained similar views with Fauchard, and states 
that, when the fluids contained in dental vessels are too thick, 
they coagulate, putrefy, since they are confined, and act directly 
upon the tooth. He explains why it is that, when a tooth deca}^s, 
the corresponding tooth on the opposite side almost always is 
similarly and symmetrically aifected shortly afterwards. Since 
corresponding teeth, he says, commonly ossify simultaneously, 
and pursue the same order of development, so the common mor- 
bid process manifests itself in the corresponding teeth ; the large 
molars, therefore, succumb earlier to caries, if they are attacked 
during their ossification. He evidently alludes here to the ero- 
sion of the teeth (comp. p. 143). 

Hunter started with false physiological views; he regarded 
the teeth as foreign substances, in a certain degree, since they re- 
ceive nourishment only while sound and fit for service and, when 
they are diseased, they do not receive the common benefits re- 
ceived by other parts which they resemble and with which they 
stand in a certain connection. He was inclined to regard caries 
as a sort of cold gangrene or mortification, but he states, fur- 
ther, that during life there is some operation going on in the 
tooth which produces a change in the diseased part. If a por- 
tion of the tooth is dead, he says, the remaining living portion 
has not the power of throwing it off and forming an external 

* De Part du Dentiste, t. i, 1757. 
24 



370 ANOMALIES OF THE SECRETIONS. 

surface capable of supporting itself like the rest of the body. 
The caries, sometimes, though rarely, begins on the inside of 
the tooth, and in this case, the latter acquires a shining black- 
ness from the dark color being seen through the remaining ex- 
ternal shell of the tooth, and no opening is found leading to the 
pulp-cavity. 

Fox* considered the proximate cause of dental caries to be 
"an inflammation in the bone of the crown of the tooth, which, 
on account of its peculiar structure, terminates in mortification.*' 

The dental pulp, he says, becomes the subject of inflammation, 
and induces caries ; he draws a parallel between pulp-membrane 
and periosteum of bone and, evidently, confounds necrosis with 
caries. 

Thomas Bellt lays stress upon the erroneous application of 
the term caries in connection with the teeth, which, he 
not in the least analogous to true caries of bone, and prop 
the term gangrene (Brand) for the teeth ; this he define- 
mortification of some portion of the tooth, which occasions a pro- 
gressive destruction of the dental substance. He corrects the 
erroneous ideas entertained by Fox, but agrees with him in believ- 
ing that inflammation is the cause of earies, that the hard dental 
tissues give way to the inflammatory process in the manner of 
bone, that the symptoms in either case are identical and that, 
now and then, the tooth presents spots which are injected with 
the red constituents of the blood. Bell probably means by this 
the portions of dentine which are imbued with the coloring 
matter of the blood, the reddened teeth. With reference to 
the occurrence of caries which proceeds from without internally, 
he considers that those portions most removed from the nutrient 
vessels and nerves are least capable of resisting decay, as we 
know is the case in other parts of the organism. He denies 
that the destruction which occurs in artificial teeth is analogous 
to caries, and maintains the falsity of the view that caries is due 
to external causes which act upon the enamel. In him, there- 
fore, we find an advocate of the pure vital theory of dental ca: 

* Op. cit.. p. 12. 

f Anat. Phys. and Path, of the Teeth, lSo-3. p. 120. 



HISTORY OF CARIES OF THE TEETH. 371 

Desirabode* states that the different views in regard to the 
nature of caries arose from the fact that all the various patho- 
logical changes upon the crowns of teeth have been included 
under this name ; that the degenerations to which the term 
caries is applied are occasioned in part by local agencies, and 
consist in a chemical destruction of the dental tissues, which 
process takes place in a direction from without inwards ; in other 
cases, they arise from some injury to the pulp or from a congeni- 
tal defect in the dentine, and are developed spontaneously from 
within outwards. The term caries, he adds, is more applicable 
to the latter variety than to the former. 

Regnardf upholds the pure chemical theory with reference to 
dental caries, considering it to be merely a destruction by acids 
which are formed within the mouth. He adds, silk ligatures 
wound around the teeth occasion the destruction of the enamel ; 
caps applied over the teeth, whether of wax or of some metallic 
substance, promote their destruction ; human teeth, artificial 
sets and separate teeth, made of the ivory from the tusk of the 
hippopotamus, undergo destruction. 

LindererJ gives a correct description of the carious process 
in enamel and dentine, and directs attention to the light dentinal 
tissue surrounding the carious portion. Inflammation in den- 
tine, he says, is not conceivable, since it contains no bloodves- 
sels. According to his view, caries is a chemical destruction of 
the teeth, induced by the oral fluids. He distinguishes three 
stages ; in the first, the enamel is destroyed and the lime of the 
dentine is set free ; in the second, the discoloration of the pre- 
viously affected tissue becomes manifest, and in the third, the 
diseased mass liquefies, and a cavity is formed in the to©th. He 
denies the occurrence of the so-called internal caries, and admits 
that of an inherited caries only in the sense that the disposition 
is inherited. 

Ficinus§ thinks he has discovered the soil in which caries 



* Elements de Part du Dcntiste (1846), t. i, p. 220. 
f Gazette des Hopitaux, 1838. 
J Zahnheilkunde. 

§ Journal fur Chirurgie und Augenheilkunde von "Walther und Ammon, 
1846. 



372 ANOMALIES OF THE SECRETIONS. 

germinates in the " cuticle of the enamel;" the brownish, 
sometimes black deposit upon the teeth, he says, is occasioned 
by the superficial decomposition of the membrane which covers 
the enamel ; this decomposition either is consequent upon, or 
lias, as its sequel, a putrefactive process which, in part, is caused 
by the presence of myriads of infusoria in the teeth (his Denti- 
colse, which, he admits, become Biihlmann's fibres by conjuga- 
tion), and in part is developed from the first in the ordinary 
manner and occasions a gradual exfoliation of the membrane. 
The putrefaction thus induced, he continues, spreads to the 
enamel-cells, where its progress is slow, extracts their inorganic 
portions, ruptures their mutual connections and, finally, reaches 
the tubular dentinal tissue, into which it extends in a similar 
manner, but with greater rapidity, and terminates only with 
the destruction of the entire tooth. He opposes the view of 
Erdl who, from the external similarity of the deposit on the 
teeth to Protococcus, assumes the presence of a parasitic cryp- 
togam which, however, cannot germinate except upon a dental 
surface that has undergone a pathological change. 

Klenke* opposes the assertion that caries, in every instance, 
in due to destructive oral fluids, and advocates the occurrence 
of a central or inflammatory dental caries. There is a second 
form, he says, in which the dental tissues are destroyed by a 
phy to parasite which he calls Protococcus dentalis. A third 
form, the putrid, consists in a true putrefactive process, whereby, 
with the co-operation of infusoria, the dental tissues are decom- 
posed. In this he agrees with the views elaborated by Ficinus. 
In aTourth form, which he distinguishes as dissolutio die mica s. 
chronica, a disintegration of the dental tissues is occasioned by 
purely chemical means on the part of the oral fluids, and by a 
disposition inherent in the chemical combination of the dental 
tissues. 

Tomesf has extended our knowledge with regard to the path- 
ological changes presented by the cartilaginous softened carious 
dentine; he asserts that, in cross- sections, the tubules of the 



* Die Verderbniss der Zalme, 18-30. 
f System of Dental Surgery. 



HISTORY OF CARIES OF THE TEETH. 373 

latter are surrounded by a very thick sheath, the outline of the 
formative cells has been restored, in fact, by the diseased con- 
dition, the tissue is broken up, to a certain extent, into its his- 
tological elements. This appearance is not found except in 
dentine which has acquired a cartilaginous consistence, in con- 
sequence of caries ; he knows of no artificial means whereby the 
appearances, such as have been described, can be brought about. 
He also discusses the vital phenomena which, according to his 
view, are coincident with structural changes in carious dentine; 
under this head he includes an increased sensibility and even 
painful sensations, chiefly in the peripheral portion of the den- 
tine ; after the destruction of vitality in this part of the tooth 
has been completed, the sensation of discomfort, for the most 
part, passes away. The transparent zone in the vicinity of the 
carious portion, he considers to be due to the consolidation of 
the dentinal fibrils within the tubes ; a reaction on the part of 
the dentine is manifested by the calcification of its fibrils, which 
necessarily exercises a considerable influence in arresting the 
progress of disease. He refers the extraction of the calcareous 
salts to the acid condition of the mucus, especially to that of the 
gums. In many cases, he says, an acid saliva appears to cause 
a rapid destruction of the teeth. He also demonstrates the for- 
mation of new dentine on the wall of the pulp-cavity correspond- 
ing to the carious locality. 

Oudet* considers caries to be a disease which primarily attacks 
the dentine exclusively, and secondarily involves the contiguous 
portion of the enamel. 

E. Neumannf endeavored to prove the vital reactionary power 
of the dentine against the carious process; he considered the 
thickening and consolidation of the tubes and fibres, mentioned 
by Tomes, to be a thickening of the dentinal sheaths, at the 
expense of the basis-substance, together with a final obliteration 
of the canals. By means of the imbibition of carmine, he demon- 
strated, in the thickened dentinal fibres, uncolored and brightly 
colored segments, alternating with each other with considera- 

* Keoherches anatomiques, phys. et raicrosp. sur ies dents, 1862. 
f Archiv fur klinische Chirurgie, Bd. vi. 



37 i ANOMALIES OF THE SECRETIONS. 

ble uniformity, and is inclined to regard the colored portions as 
nucleiform bodies. Upon an eroded ivory peg which had been 
driven into a bone in the treatment of a pseudarthrosis, he was 
unable to detect such a condition as is presented by carious den- 
tine ; this fact he regards as a confirmation of his view, and 
considers that there is a marked correspondence between the 
changes in dental caries and the phenomena presented in caries 
of bone. Between caries of the teeth and of bone, he says, the 
distinction is purely formal, depending upon the difference be- 
tween the forms of the cellular elements contained in each of 
the tissues respectively, the roundish bone-cells on one side and 
the elongated dentinal fibres on the other, which latter become 
thickened and detached. He observed a calcification of the 
dentinal fibres only in one instance, and remarks that the latter 
is referable to an excessive disposition to the deposit of calcareous 
salts at the expiration of an inflammatory process, a phenomenon 
which is observed in bone. 

Magitot* holds the opinion that caries is a purely chemical 
action upon the enamel and dentine, and denies the existence 
of a caries interna. The reaction on the part of the dentine, 
he says, is manifested usually by the appearance of a cone or 
white zone, which is occasioned by obliterated dentinal canals : 
secondary dentine sometimes is formed at a later period in the 
pulp ; the saliva, he observes, is the cause of the caries when it 
becomes the seat of acetous fermentation, or the vehicle of for- 
eign substances which act directly upon the enamel and dentine. 
Upon the authority of numerous experiments, he asserts that 
caries may be induced artificially by imitation of those condi- 
tions which occur in the oral cavity, and that this artificial 
caries presents the same characters as the natural form, with 
the exception of the reactionary phenomena. 

Hertzf undertook the examination of caries induced by artifi- 
cial fluids, according to Magitot's method, and also of a number 
of artificial teeth which became carious within the mouth. 
He found merely a brownish-yellow color of the dentine, to- 
gether with disintegrated and decomposing, larger or smaller 

f Virohow's Archiv, Bd. xli. 



HISTORY OF CARIES OF THE TEETH. % 875 

portions of basis-substance. He found nothing abnormal in the 
dentinal fibres, and hence he coincides with the view that the 
changes in the dentine in natural caries correspond to a vital 
process. As pathological appearances of the dentinal fibres, he 
mentions that they appear swollen, cloudy, homogeneous in 
character, replete with fat-granules, and take up calcareous 
salts, and these he considers to be primary affections. 

Th. Leber and J. Rottenstein* assert that there are no recorded 
observations which authorize the. assumption of an active reac- 
tion, a kind of odontitis, on the part of the dentine in caries of 
the teeth, and that caries does not depend upon the changes re- 
ferred to by Tomes, Neumann and others, although the occur- 
rence of very slight histological changes in the dentine at the 
commencement of the process cannot be denied with absolute 
certainty. They came to the conclusion by proving that artifi- 
cially inserted human teeth, which have become carious within 
the mouth, and also carious teeth, manufactured out of ivory 
from the hippopotamus, displayed the microscopic changes in 
the dentine which were regarded as proof of a vital process in 
the dentine. They treated leptothrix in the dentine with iodine 
and acids and obtained a violet color of the widened dentinal 
canals which were filled with a minutely granular mass, and 
consider it to be indisputable that the elements of the fungus 
proliferate within and extend the canals, sometimes to a consid- 
erable degree. The fungus, they add, apparently is incapable 
of penetrating enamel of normal hardness; even normally hard 
dentine oifers considerable resistance to its entrance, if, indeed, 
it permits it in the least. When, however, in consequence of 
the action of the acids within the mouth, the enamel and den- 
tine have lost, somewhat, their power of resistance, or a breach 
of substance, however small, has been produced upon the sur- 
face of the dentine, then it becomes possible for the fungus ele- 
ments to penetrate into the interior of the dental substances, 
and by their proliferation, particularly in the dentine, to occa- 
sion a more rapid progress of the softening and destructive pro- 
cess than would have been the case under the action of the acids 

* Caries der Zahne, 1867. 



376 ANOMALIES OF THE SECRETIONS. 

alone. A very marked destruction of the teeth within the 
mouth, they say, requires a participation of the fungus; in the 
earliest stage, only while the surface of the tooth is still smooth 
and intact, is the fungus underaonstrable, and hence it is appar- 
ent that in this stage, that of dry caries properly speaking, the 
changes are to he ascribed exclusively to the action of acids. 

From this cursory survey of the various theories with regard 
to caries, of the -vital, chemical, and parasitic, with their combi- 
nations, the advance in our knowledge becomes apparent, al- 
though the interpretations of phenomena, in many cases, present 
wide differences. A critical consideration of the views which 
have been adduced will be found in the following pages, in con- 
nection with the theory of caries. 

Appearances Presented by the Enamel in Caries. — Be- 
fore entering upon the consideration of these, we must allude to 
the cracks or fissures in the enamel, which have an importance 
in connection with the development and extension of caries. 
During life, these interruptions of continuity are observed very 
frequently upon the otherwise healthy, sound teeth of young 
persons and especially upon those of persons in advanced age. 
and they follow, as a general rule, the planes of cleavage in 
the enamel (comp. p. 80). 

Upon close inspection, by means of a lens, they are found to 
be much more numerous than one would suspect at first. Not 
infrequently, besides the principal crack, we find a number of 
smaller, secondary ones which unite, in some cases, so as to form 
a web, and in others, diverge in the manner of rays. Their 
edges gape only in exceptional cases and, consequently, there is 
presented an appearance of narrow fissures. 

The cracks vary in character in the different kinds of teeth. 
The enamel of the incisors not infrequently presents upon its 
labial surface one or even several straight fissures, reaching from 
the neck to the incisive edge: usually they are not so deep as 
to form a gap, but are limited to the superficial layers. Oblique 
cracks, also, occur upon the lateral portions of the crowns of 
these teeth and extend also from the incisive edges, from which 
particles of the enamel have been broken away. Irregular, 
zigzag fissures sometimes extend from the edges towards the 



APPEARANCES PRESENTED BY CARIOUS ENAMEL. 377 

neck. Sometimes, when the edges are worn down, the fissures 
extend transversely or obliquely, subdividing here and there, 
across the abraded surfaces and, consequently, encroach upon 
the abraded dentine. 

Upon the canines, they generally extend from the coronal 
apex towards the neck. Upon the bicuspids and molars, longi- 
tudinal fissures extend from the coronal cusps. They are met 
with, also, in the grooves of the latter teeth. When the cusps 
are worn away, dichotomous fissures are frequently found upon 
the abraded surfaces. 

Towards the neck of the tooth, where the enamel becomes 
thinner, closely approximated fissures, which often intersect 
each other, are of very frequent occurrence upon all the teeth. 
The stellate form is not very common and usually originates in 
a minute defect in the enamel. Longitudinal fissures in the in- 
terstitial frictional surfaces of the dental crowns are quite com- 
mon. Teeth with numerous depressions in, and excrescences 
upon, the enamel often contain a large number of extremely ir- 
regular fissures. 

Fissures which communicate in the interior of the substance 
are frequently met. with in the dirty-grayish or brownish-discol- 
ored portions from commencing caries, and in these cases the 
conditions presented by the membrane of the enamel are of 
especial interest. If the latter be removed in the ordinary way, 
by means of dilute hydrochloric acid, manifold perforations are 
brought into view, partly in the transparent, colorless, partly in 
the thickened portions of the membrane which is covered with 
the matrix of leptothrix and contains deposits of pigment ; these 
are distinguished as simple, resembling cleft-like gaps, and com- 
pound. The latter form a system of ramifications which gradu- 
ally become more narrow, presenting an appearance not unlike 
that of the veins on the leaf of a plant, and are more likely to 
be found in that part corresponding to the thinner portion of 
the enamel layer towards the neck of the tooth. The mem- 
brane in the latter localities usually is covered with a uniformly 
disposed, firmly adherent leptothrix mass (Atlas, Fig. 83). 

A minute interruption of continuity, which is confined to nar- 
row limits, manifests itself in the commencement of caries, espe- 



378 ANOMALIES OF THE SECRETIONS. 

cially in that developmental stage in which a quite light, more 
or less white spot makes its appearance. As the continuity of 
the enamel prisms becomes interrupted, the corresponding por- 
tion of the enamel loses its transparency, and, with the more 
extensive rupture of their cohesion, the enamel crumbles away, 
leaving a breach of varying depth. The surface of the enamel, 
corroded as it were, is uneven, rough and full of holes. "White 
spots occur here and there, independently of caries, and indi- 
cate an imperfect development of the enamel or a localized (for 
some time at all events), permanent lax condition of the enamel 
prisms. 

The pigment deposits in the enamel, in connection with caries, 
form a very conspicuous feature. With reflected light they pre- 
sent various shades of color, from brownish-red to blackish- 
brown, a dark-gray, yellow, or yellow-gray; with transmitted 
light, they are tinged with a vivid brownish-red, light reddish- 
yellow or deep-yellow color. The pigment is limited to a small 
portion at first and gradually traverses the entire thickness of 
the enamel ; the darker shades, therefore, are found near the 
surface, and the lighter, in the deeper enamel layers; a dark zone 
is commonly found in the deepest layers adjoining the unaffected 
portions of the enamel (Atlas, Figs. 87 and 88). 

The outlines of the portions containing deposits of pigment 
present variations which depend principally upon their local 
where the enamel dips down into the grooves or becomes atten- 
uated towards the neck of the tooth, the pigmented portions usu- 
ally occur in streaks with irregularly wavy outlines. The decol- 
orations, particularly in the thicker portions of the enamel, fre- 
quently occur in the form of a cup or cone, the base of which is 
directed outwards, sometimes, but more frequently inwards to- 
wards the dentine. 

Occasionally in chronic caries, streaks or spots are very con- 
spicuous where the transparency of the enamel is increased; 
these occur within circumscribed limits in the vicinity of a por- 
tion discolored by the presence of brown pigment, and are 
brought very clearly into view by means of the lens and with 
reflected light. The structure of the transparent enamel has a 



APPEARANCES PRESENTED BY CARIOUS ENAMEL. 379 

more homogeneous appearance since the transverse markings of 
the prisms are less distinctly perceptible than, in other localities. 

If we examine thin sections of carious enamel containing de- 
posits of pigment, and trace out its various shades of color, we 
find that the structure of the enamel is wholly unrecognizable 
where the coloring matter is most abundant or the brown pre- 
sents a tinge of gray, while in the portions containing less pig- 
ment, the transverse markings of the enamel are very con- 
spicuous and the transverse striations of the elementary parts 
are even broader in appearance. 

The diminution in the consistence (compactness) of the por- 
tions which become the seat of deposits of pigment in connection 
with caries is an important element in the process. Scrapings 
from the surface of a section of the enamel present a mortar- 
like disintegration, powdered fragments of enamel. The prisms 
lose their proper transparency and the homogeneity of their 
contents, which acquire a finely-porous appearance, is de- 
stroyed. 

In order to obtain a definite idea of the appearance of the 
enamel-cap ivhen it presents fissures or carious spots, it is ad- 
visable to detach the cap by means of a fifty per cent, solution 
of sulphuric acid, as recommended by H. Beigel. For this 
purpose, teeth should be selected in which the caries is not very 
far advanced, because, in the later stages, the caps easily crum- 
ble. In this way, a clear and definite view of 
the fissures may be obtained. In the molars, fig. 99.* 

deep cracks are quite common, extending from 
the carious portion across the masticatory, and 
along the lateral wall of the enamel-cap, and 
also radiating from the affected portion (Fig. 
99). 

At the same time we are enabled to compare 

* Fig. 99 shows numerous fissures with several holes and clefts in the 
enamel-cap of a molar, in a view of the internal or dentinal surface. Most 
of the fissures are deep; some of them extend from the carious portions of 
the masticatory wall upon the annular or lateral wall of the enamel-cap, 
here and there presenting ramifications. In this case, several holes and 
clefts with sharp edges and no deposit of pigment in the adjoining portions 




Fig. 100.* 




380 ANOMALIES OF THE SECRETIONS. 

the appearances presented by the carious locality upon the ex- 
ternal and internal surfaces of the enamel-cap. It may readily 
be shown that, when the pigment deposit consequent upon caries 
is limited to a scarcely perceptible dark-brown, minute dot upon 
the masticating surface, it is more extensive upon the internal 
or dentinal surface where it has a roundish or jagged outline. 
When caries in the groove of a molar tooth is displayed in the 
form of a very narrow streak containing pigment, the affected 
portion upon the internal surface of the cap measures a fourth 
of a millimetre and upwards. When a cleft-like loss of substance 
is occasioned by caries, the portions around the margins of the 
gap contain deposits of pigment and frequently 
are thickened somewhat (Fig. 100). The pig- 
ment deposits, consequent upon caries, which 
occur in the contiguous coronal surfaces and 
usually have a light or grayish-brown color, 
penetrate the entire thickness of the enamel at 
first only in the thinnest portion near the neck 
of the tooth. 
It happens, sometimes, that a portion of the summit of the 
still hard dentine, with a brownish-yellow pigment deposit cor- 
responding with the carious locality, remains unaffected, while 
the rest of the dentine is destroyed by the boiling dilute sul- 
phuric acid. It has not yet been determined whether or not a 
casual, unusually great power of resistance on the part of the 
dentine is to be assigned as the reason for this occurrence. 

If we select a series of teeth which are affected with caries in 
its earlier stages and belong to the different periods of life, and 
treat them with very dilute hydrochloric acid, it may readily be 

of the enamel are to be observed ; these are not the results of abrasion or 
caries, but are to be regarded as defects in the formation of the enamel. 
Magnified '2 diameters. 

* Fig. 100 — Interior view of the enamel-cap from a molar affected with 
chronic caries. The latter occurred in the crucial groove. The waii 
responding; to the masticating surface presents a few gaps and several dark 
spots ; the enamel tissue in the vicinity of the former and in the latter had 
a dirty-grayish and reddish-brown color, and is fissured and full of excava- 
tions; the carious affection is more extensive upon the inner than upon the 
outer surface. Magnified 2 diameters. 



APPEARANCES PRESENTED BY CARIOUS ENAMEL. 381 

demonstrated that the portion of the detached enamel membrane 
corresponding to the carious locality has undergone a 'perceptible 
thickening. The transparent membrane, moreover, where the 
transition into the carious portion is apparent, is clouded, brit- 
tle and variously stained. The colors vary between gray, 
grayish-brown, brownish-yellow, syrupy-brown, reddish-brown, 
and reddish-yellow. With regard to the carious localities, it is 
to be borne in mind that one has to do not only with the mem- 
brane of the enamel, but also with the organic remains of the 
enamel. 

The frequent gray cloudiness presented by the detached mem- 
brane is found to be due to a uniformly-diffused mass of granules 
of nearly equal size and arranged side by side and over one 
another at uniform distances. The molecular mass is the so- 
called matrix of leptothrix buccalis which is united so intimately 
with the enamel membrane and the organic remains of the 
enamel that together they form an inseparable whole. The 
thickness of the matrix varies, and the thickening of the mem- 
brane is due, in a great measure, to the latter ; the brittleness 
and friability of this membrane, also, is occasioned by the super- 
position of the matrix. As proof that the latter appertains to 
the leptothrix may be adduced the fact that it is not uncommon 
to find tufts of leptothrix threads hanging from the edges of the 
granular mass. 

The brown portions present light or dark-brown, transparent, 
homogeneous masses which are fissured in such a manner as to 
display a lamina composed of irregular polygons. The perfora- 
tion of the enamel-membrane, mentioned above as resembling 
the nerves of a leaf, presents a strong resemblance in its con- 
figuration to the brown mass in question ; the latter, however, 
is thicker and proceeds from the enamel which is deprived of its 
calcareous salts, transformed into a homogeneous mass and 
foraminated. 

The familiar mosaic appearance produced by the transverse 
division of some of the prisms is beautifully shown, in some 
cases, after the extraction of the calcareous salts from carious 
enamel. Some of the prisms contain a homogeneous, highly 
refracting, light or dark brown, and others a granular, mass of 



382 ANOMALIES OF THE SECRETIONS. 

a similar color (Atlas, Fig. 84). The persistence of the contours 
of the enamel prisms in places after treatment with acids is un- 
explained, at present. Possibly it may be due to the prolifera- 
tion of a leptothrix mass into the decalcified enamel. 

The carious enamel sometimes, also, is transformed into a 
coarse-granular, brown mass ♦ now and then the granules are 
blended together and are to be regarded as the organic remains 
of the shrivelled enamel-prisms. The mass is intimately united 
with the enamel-membrane, upon the outside of which, in many 
places, is located the matrix together with the attached threads 
of leptothrix. 

When the deposits of pigment impart a blackish-brown color 
to the carious enamel, the prisms are no longer distinguishable. 
After the extraction of the calcareous salts from the enamel, 
there is left, sometimes, a brittle, friable, blackish-brown mass 
which presents sharp and angular edges when broken. In the 
later stages, the enamel-membrane acquires a syrupy-brown 
discoloration. 

When the carious enamel presents superficial greenish spots, 
this color is participated in by the externally-attached matrix 
of leptothrix, the enamel-membrane and even the organic re- 
mains of the enamel-prisms, to a varying degree. 

If so-called eroded, cribriform, foraminated [honeycombed], 
and, consequently, irregularly-developed enamel, which is af- 
fected with commencing caries, be decalcified, the enamel-mem- 
brane will display an alveolate appearance, i. e., it presents 
round, sharp-edged pits of various sizes, within which the mem- 
brane is thinner and perhaps wanting entirely, here and there, 
and a leptothrix-mass has taken up its abode. Between the 
light-colored alveoli lies a yellow, syrupy -brown substance. 

In many cases, the remaining organic matter of the enamel 
from the teeth of old persons, which are affected with commencing 
caries, presents the appearance of a diffluent, coagulated, trans- 
parent, structureless, effused substance, in the interstices of 
which is lodged a molecular, dirty-gray leptothrix mass. 

Usually in the course of the process, an undermining caries 
of the enamel is met with, i. e., the caries is more extensive in 
the deeper layers of enamel than is apparent externally upon 



APPEARANCES PRESENTED BY CARIOUS ENAMEL. 383 

the surface, just as if the process commenced in a groove, de- 
pression, or fissure. The particles of enamel crumble away 
and are detached, leaving a gap or a pit which increases in ex- 
tent in the deeper layers. The undermined portion may easily 
be broken away, when the enamel upon the excavated surface 
may be scraped off, displays a chalky or mortar like disintegra- 
tion, often presents a dirty-brown color and contains the frag- 
ments of enamel-prisms. As might be anticipated, the dentine 
is exposed to greater danger by this undermining process; it is 
denuded to a greater extent and subjected to the action of in- 
jurious external agents. When the deposit of pigment in the 
carious enamel takes place in the form of a cone with its base 
directed externally, the affection of the dentine is confined to 
more narrow limits. 

Heider informed me that caries of the enamel frequently 
escapes clinical observation at its commencement, and that this 
is the more likely to be the case since at this stage the disease 
gives the patient no uneasiness and, usually, occurs at points 
which cannot be seen except with difficulty. By a careful ex- 
amination with a very fine probe and mouth-mirror, a slight 
roughness is detected in the enamel which may readily be re- 
moved with a sharp instrument. By means of the mirror the 
color is brought into view ; this varies according to circumstances, 
and is particularly distinct with those teeth which it is possible 
to examine in the mirror with the light transmitted through 
them, as, for instance, with the posterior surface of the incisors 
when they are examined in the mirror with the light falling 
directly upon them. A diffused cloudiness with a quite dark 
central portion characterizes the primary appearance of caries, 
before a pit-like breach of substance is produced by the disin- 
tegration of the enamel. Observed in the above manner, the 
color of the spot varies from a chalky-white to a bluish-white, 
and is gray, brown, and black. 

These different colors, however, do not correspond to different 
stages of the process, but characterize the various modifications 
of the same. The lighter the spot, the deeper extends the de- 
struction and the more rapid is the progress of the disease. The 
darker the color, the more limited and circumscribed is the dis- 



384 ANOMALIES OF THE SECRETIONS. 

colored portion of the enamel, and the slower is the course of 
the affection. 

Let the discoloration be what it may, the subsequent patho- 
logical changes in the enamel present a tolerable degree of uni- 
formity. The connection existing between its constituent ele- 
ments becomes broken. Oftentimes, also, a fissure may be 
detected, which bisects the discolored portion. If, however, 
this is not the case, the enamel is always found to be perforated 
with holes, is friable, breaks up and crumbles away, and in this 
way the already more or less softened dentine becomes denuded. 

In the primary stage, that of discoloration, the process which 
has been described is entirely painless. When perforation com- 
mences, patients who are attentive to their teeth experience, at 
first, especially during the mastication of a very firm substance, 
an unpleasant sensation which is induced by partaking of a< 
fruit, syrup and, sometimes, even by sudden changes of tem- 
perature. Generally, however, this sensation esca [ra- 
tion and the patient is first made aware of the destruction which 
has taken place, by the occurrence of occasionally severe, but 
transitory pains, occasioned by the impaction of particles of food 
within the deep cavities where the surface of the dentine has 
been extensively denuded. 

Appearances Presented by the Dentine in Caries. — 
That portion of the dentine which lies beneath the enamel-cap 
becomes involved before the deposit of pigment in the carious 
enamel has reached the dentinal boundary (Atlas. Figs. 87 and 
88). The affection of the dentine is manifested by a diminit 
translucency and a discoloration of the corresponding portion of 
the dentinal crown. The portion adjacent to the enamel boun- 
dary has a very intense, reddish-brown color: this passes into, 
a reddish-yellow which, finally, becomes a straw color towards 
the central portion. The opaque condition forms a greater or 
less contrast with that of the adjacent dentine. In most cas 
the affected portion of the periphery of the dentine assumes the 
form of a cone, the base of which, directed outwards towards 
the enamel, is broad in comparison with the discolored portion 
of the enamel. The apex of the cone is directed towards the 
central portion, and it is evident that the configuration of the 



APPEARANCES PRESENTED BY CARIOUS DENTINE. 385 

cone is occasioned by the radiation of the dentinal canals. This 
disposition, however, does not always obtain in respect of the 
opacity and discoloration; it is far more common to find lateral 
prolongations from the carious dentinal cone. The yellowish 
pigment not infrequently is distributed with great irregularity, 
extends to a considerable depth in the carious dentine, and gives 
rise to the appearance of insulated patches of yellowish, discol- 
ored dentine, in transverse and longitudinal sections. 

The still compact, affected portions of the dentine present a 
clouded appearance, due in part to the presence of grains which 
have a linear arrangement, are spherical, for the most part, 
sometimes, also, elongated, and fill the cavities of the dentinal 
canals. This granular condition is very perceptible, also, in the 
yellowish discolored portions and even in the interglobular masses. 
The cloudiness in the canals not infrequently is due to a molec- 
ular condition, and in this connection I will merely remark that 
it is morphologically identical with that met with, both in the 
vicinity of the abraded surfaces and of the cement, in the canals 
of senile teeth which have been worn clown to the dentine but 
do not contain the least trace of caries. 

It is a difficult matter to determine the nature of these grains, 
but I have no doubt that they belong, for the most part, to liquid 
fat. If thin sections of the dentine in question be subjected to 
the action of dilute hydrochloric acid, a number of drops, ex- 
actly resembling fat-globules, always make their appearance, 
both upon the surfaces and edges of the sections; indeed, they 
are often found in the interior of a canal. If a section of den- 
tine of this description be decalcified completely, by means of 
dilute hydrochloric acid, and then carefully boiled with the 
same acid, in order to effect the familiar isolation of the pro- 
cesses of the dentinal cells, we obtain, in some places, grains 
arranged in the form of a chaplet and diminishing in size to 
that of minute molecules, and in others, varicous processes, the 
contents of which present the glitter of fat. Many of the pro- 
cesses remain entirely free from this metamorphosis; from many 
others the fat obviously has been pressed out and the globules 
have united to form drops. The appearance is exactly similar 
to that obtained from senile, much worn dentine (Atlas, Fig. 95). 

25 



386 ANOMALIES OF THE SECRETIONS. 

If, on the other hand, the question be asked if the fine gran- 
ules do not belong to leptothrix, in my opinion, a negative reply 
should be given. I have been unable, in this primary stage of 
the carious affection of dentine, to obtain a reaction from the 
treatment of leptothrix with iodine and acids, according to the 
method suggested by Leber and Rottenstein. 

The discoloration of the carious dentine extends to the canals 
and intertubular tissue and is intense even in very thin, trans- 
verse sections. The interglobular masses, also, contain deposits 
of pigment. Coincident with the development of the opacity 
and the pigmental degeneration, in the commencement of the 
carious affection of the dentine, an increased } Iran slue ency is ob- 
served, frequently, in the portions adjacent to the boundary of 
the carious portion. With reflected light, these portions have a 
horny appearance, similar to that found in senile roots, and, with 
transmitted light, they present hyaline bands and spots. The 
focus (Herd) of the caries is surrounded by a diaphanous halo. 
The opaque, carious dentinal cone, therefore, is invested by a 
translucent zone, extending from the periphery towards the cen- 
tre; around a more spherical, carious portion of the dentine, a 
crescentic diaphanous halo is met with sometimes. The light 
portions, finally, vary exceedingly in respect of their outlines, 
according to the form in which the carious limits are extended, 
being radiated, kidney-shaped, &c. (Atlas, Fig. 91). 

No diminution in the compactness of such dentine can be de- 
tected, and it is an easy matter to prove the impossibility of the 
admission of air into the desiccated dentinal canals. I have 
been unable, in thin sections, to discover a further anomaly 
in the tissue. J. Tomes* speaks of a consolidation of the den- 
tinal fibrils as being the cause of the translucency, and regards 
the fibrils as calcified, since, in thin sections, made with a sharp 
knife from a well-selected tooth in the direction taken by the 
dentinal tubes from the discolored portion, he saw the fibrils 
within the tubes broken into short fragments. These statements 
may be correct, but Tomes has yet to prove the calcification of 
the fibrils, since he neglected to try the reaction with acids : 

* Op. cit., p. 313. 



APPEARANCES PRESENTED BY CARIOUS DENTINE. 387 

moreover, the evidence obtained from preparations made in such 
a manner are not to be depended upon. 

If the carious, discolored, but still compact dentine remains 
denuded for some time, exposed to the action of external agents, 
and any acid be allowed to act upon its surface, a decalcifying 
process will ensue and that condition will be induced which is 
termed cartilaginous softening. In many cases, this is a very 
slow process and even appears to be arrested for a time, while 
it takes place rapidly in some cases. The latter form is desig- 
nated commonly as acute, moist caries, in contradistinction to 
the former which, more properly, is termed chronic. 

When the dentine has become deprived of its calcareous salts 
to an extent sufficient to admit the insertion of a needle, a super- 
ficial disintegration ensues. Leber and Rottenstein, therefore, 
with reason, divided the carious affection of the dentine into 
two stages which, however, cannot always be nicely discrimi- 
nated, a preparatory stage of decalcification and softening and 
a stage of direct disintegration. 

Upon the examination of dentine which has undergone the 
cartilaginous softening and may be cut with a knife, no marked 
change can be detected, except a yellowish, reddish-yellow, red- 
dish-brown discoloration; the dentine presents an appearance 
as if it had been decalcified by means of hydrochloric acid and 
subsequently dyed. Localities, however, are observed, chiefly 
in cases where the softening has been very extensive, in which 
the dentine has undergone such a remarkable alteration that it 
can scarcely be recognized as human dentine, a metamorphosis 
which was discovered by J. Tomes and has been confirmed by 
numerous writers. 

In sections made in a direction transverse to the axes of the 
radiating dentinal canals, a greater or less number of canals are 
met with, whose limiting walls (the so-called dentinal sheaths) 
describe unusually large circles, and whose cavities are replete 
with a mass which has, in some places, a homogeneous, in others, 
a molecular appearance and forms convex projections beyond 
the surface of the section (Atlas, Fig. 92). The transverse di- 
ameters of the widened and filled canals vary, some being at 
least three times as large as others. The intertubular tissue 



388 ANOMALIES OF THE SECRETIONS. 

presents a molecular cloudiness and is beset with grains having 
the appearance of fat. In sections made parallel to the long 
axes of the canals, they are quite clearly seen to be unequally 
filled by the foreign mass, since they present manifold varicosi- 
ties and constrictions which, also, explain the variations in the 
diameters of the widened canals. 

If a section made in the direction of the varicous canals is 
boiled for some time in water or in very dilute hydrochloric 
acid, until it begins to break up into delicate, fimbriated tufts, 
in other words, if the dentinal fibres or processes of the dentinal 
cells are isolated, a still more definite idea of the various degrees 
of thickenings and knotty swellings of the- same may be ob- 
tained. A molecular mass covers these fibres nearly every- 
where ; sometimes, also, they present transverse fissures which 
give to them a peculiar, as it were, scarified appearance. Mi- 
nute grains, also, like the head of a pin, rest upon the fibres at 
tolerably uniform intervals from one another and are highly 
suggestive of Micrococcus.* Lateral branches are given off* 
from the fibres at fixed angles (Atlas, Fig. 95). In consequence 
of the blending of the intertubular tissue, a considerable number 
of fat-globules are produced, which, in many places, impart a 
notable cloudiness to the cartilaginous softened dentine. 

The question naturally arises, what is the nature of the mass 
which fills the canals ? Leber and Rottenstein, by a fortunate 
application of an iodine solution and acid, succeeded in demon- 
strating the proliferation of leptothrix buccalis in the softened 
dentine. One may readily convince himself, both in longitudi- 
nal and transverse sections, of the violet color which is im- 
parted to the contents of the canals. Hence, by their prolif- 
eration, the grains of leptothrix occasion the manifold swellings 
and varicous enlargements of the fibres, and are so closely ce- 
mented together, that their connection cannot be broken even 
after the action of heated hydrochloric acid. 

Upon a very close examination of the disintegrating portions 
of the superficial softened dentine, the matrix of leptothrix 
may be found everywhere in the perforations ; irregular chan- 

* Comp. Kavsten, Cheuiismus der Pflanzenzelle, 1869. p. 25. 



APPEARANCES PRESENTED BY CARIOUS DENTINE. 389 

nels, spherical cavities, which are found, here and there, still 
connected with a thickened fibre, are replete with the matrix. 

In consequence of the superficial disintegration of the den- 
tine, there arises, at first, a shallow indentation which, however, 
shortly acquires larger dimensions when the caries undermines 
the dentine, as is the case nearly always in the acute form. A 
cavity with a narrow outlet is formed which contains the so- 
called carious matter. Particles of food, forced into this during 
mastication, easily become impacted, and give rise to a process 
of fermentation ; sometimes, innumerable monads are found 
moving in the fluid vehicle, and upon the wall of the cavity are 
attached large masses of leptothrix and linked chains of oidium. 
Fragments of dentine, which have not been decalcified, some- 
times exfoliate during the undermining process and are of fre- 
quent occurrence within the cavity. In the dried condition, the 
wall of the cavity has a gray, grayish-brown, dirty yellowish- 
brown color, or it is not uncommon for it to be colorless, like 
asbestos, and the loosened dentinal layers may be detached in 
fragments or thin lamellae, by means of a needle. 

If the carious cavity has extended so far that nothing but a 
thin layer of dentine separates it from the pulp-cavity, or it has 
reached the pulp, then occur those constant pains which are in- 
duced by inflammation of the pulp (compare p. 176). 

Exceptional cases occur where the destruction of a large por- 
tion of the crown of the tooth may be accompanied by very 
slight, if any, pain. This fact may be ascribed, in part, to a 
generally diminished sensibility on the part of the individual, 
but, for the most part, it is due to an atrophy, a calcification, or 
a dentinal new-formation corresponding to the carious locality. 

Cases of caries of the dentine which runs a chronic course 
differ from the foregoing in that the decalcification and disinte- 
gration progress slowly. While, in acute cases, months only, in 
chronic cases as many years are required for the destruction of 
the crown of a tooth. Between these two extremes, a large 
number of cases occur which have a longer or shorter duration. 
In the moist, acute caries, the discoloration of the affected den- 
tine is of a light shade, the lighter the shorter the duration of 
the disease, and the cartilaginous softening acquires a notable 



390 ANOMALIES OF THE SECRETIONS. 

extent, while, on the other hand, in the chronic form, the dis- 
coloration is of a darker hue, and the consistence of the nearly 
black dentine is slightly diminished. The reaction of the con- 
tents of the carious cavity with litmus-paper, also, furnishes a 
familiar element of distinction between the two forms, namely, 
a more strongly marked acid reaction is given in cases where 
the destruction is most rapid. The cartilaginous softened layer 
of the dentine has a marked acid reaction, while in connection 
with chronic destruction the latter is not decided. 

The dark shaded, consistent, carious dentine occasionally dis- 
plays a very narrow zone of cartilaginous softening, but in well- 
marked chronic cases, this cannot be identified. In the latter, 
therefore, we have to do with very dry caries. A dark powder 
containing the fragments of dentine may be scraped off by 
means of a sharp knife, and besides the dark-brown discolora- 
tion, no other anomaly is presented by the dentine. I have 
been unable to satisfy myself of the calcification of the fibrils 
in these cases. 

In the course of chronic caries, the dentinal layers exfoliate, 
the surface of the affected portion is rough, as if it had been 
scratched with a sharp instrument ; as the dentine disappears, 
there is left, at. first, a minute, gradually enlarging, carious in- 
dentation with a sharp margin and a blackish-brown discolored 
wall. 

When the coronal dentine is affected primarily, as sometimes 
happens when the masticating surfaces have been worn away 
very much, bands and spots make their appearance, having 
a color varying between dark-brown and black and invested 
by a quite broad, light-brown uniform zone. Both discolora- 
tions extend nearly to the wall of the pulp-cavity. In such 
cases, frequently, it is a matter of doubt whether we have to do 
with dental caries or with senile necrobiosis. One must be care- 
ful not to pronounce every brownish discoloration of the den- 
tine to be caries (compare remarks upon the senile changes in 
dentine, p. 242). 

Thin sections of dentine affected with well-marked chronic 
caries display a dark pigmental degeneration, but no other 
structural change ; it is especially noticeable that, even after a 



APPEARANCES PRESENTED BY CARIOUS CEMENT. 391 

preliminary decalcification, they present no expansions of the 
dentinal canals containing proliferating leptothrix and, more- 
over, that grains and threads of leptothrix are rarely met with 
upon the surface of the carious dentine. 

Appearances presented by the Cement in Caries. — Caries 
makes its appearance upon the neck of the tooth, usually in the 
vicinity of the border of the enamel, and commences in the 
form of a discoloration (barely perceptible at first, and of a 
brownish tinge) of the cement layer which, in this locality, is 
very thin. In a short time, the latter is destroyed, the dentine 
becomes affected, the enamel attached to the neck becomes un- 
dermined by the formation of a carious excavation and projects 
in the form of a lamella with sharp edges. The excavation, 
shallow at first, becomes more extensive as the carious process 
spreads from the border into the adjoining portions of the neck. 
A cavity of considerable size is developed by the carious pro- 
cess, which usually occurs in the more acute form, and the 
danger to the tooth is measured by the extension of the caries 
around the neck. 

If a portion of the root of the tooth is deprived of its bony and 
membranous covering, in consequence of the wasting of the alve- 
olus, the carious process may attack the cement of the root pri- 
marily and produce one or several breaches of substance, up to 
the size of a pin's head, which extend through the entire thick- 
ness of the dentine and occasion a denudation of the correspond- 
ing portion of the root-pulp, as the disease advances. These 
carious excavations usually have sharp edges, are patelliform 
and, occasionally, occur without an affection of any other por- 
tion of the tooth. 

Caries of the cement presents, at first, a more or less circum- 
scribed, yellow or brown discoloration, without any other change 
of the bony substance. Perforations immediately begin to 
make their appearance, which extend from without internally 
and give rise to a disintegration and breach of the superficial 
layers of the cement.. The surface of the discolored cement 
also acquires an eroded appearance and is beset with shallow 
pits with serrated edges. When the caries extends from the 



892 ANOMALIES OF THE SECRETIONS. 

cement to the dentine, the latter becomes perforated, usually in 
the direction of the dentinal canals. 

Extension of Caries to the Roots of the Teeth. — If the 
coronal portion be undermined by caries, extending from the 
masticating surface, the surfaces adjacent to the contiguous 
teeth, or from the neck, so that a large cavity with a fragile, 
shell-like wall is formed, the latter gradually crumbles away 
leaving merely the corresponding roots. Although the carious 
process may have run a well-marked acute course in the coronal 
portion, it is much more protracted in the roots, and as Hunter 
asserted long ago, it is a rare occurrence to meet with a root 
which has been excavated as far as its apex.- The process ap- 
pears to be suspended, sometimes, or at all events, to advance 
very slowly. The carious excavation usually is shallow, the 
elevated edges frequently are attenuated and jagged. In one 
instance, only, I have met with a flask-shaped cavity with a nar- 
row outlet. The extremities of the root become blunted, rounded 
and discolored, this condition being more conspicuous, the 
smaller the portion of the root which is retained. 

After the destruction of the coronal pulp, the inflammation 
assumes a decided chronic character in the radical pulp, and 
we find nothing but the scanty remains of the latter in the carious 
roots, though the chronic inflammatory process may have been 
terminated for a long time. Atrophic, shrivelled, connective 
tissue with a tinge of dirty-yellow and brown, here and there, 
presenting barely traces of net-like atrophy, accumulation- 
crystals of haematoidin and calcareous grains compose the 
principal constituents. 

A chronic inflammatory condition of the root-pulp, in quite 
rare cases, leads to a new-formation of bony substance or osteo- 
dentine upon the interior surface of the root-canal and may 
even give rise to the development of anastomosing, rapidly ob- 
literated vascular canals which are prolonged from the 
of the root-pulp into the dentine and, in places, are invested by 
a layer of globular masses and even by an accessory, well-devel- 
oped bony substance with a sharply-defined, indented border di- 
rected towards the dentine: this substance occasionally foil 



CARIES OF THE DIFFERENT KINDS OF TEETH. 393 

the course of the root-canal, forming a complete investment 
about it (Atlas, Fig. 98). 

The periosteum of the root usually is notably thickened and 
sclerosed, and consequent upon this occur hypertrophies and 
interstitial proliferations of the cement into the dentine. On 
the other hand, a marked resorption may occur, involving either 
the entire cement or portions of it and causing numerous 
breaches of substance in the hypertrophic cement, in consequence 
of which the surface of the carious root sometimes presents deep 
excavations and is rough to the touch (comp. p. 273). 

The carious discoloration of the dentine usually does not ex- 
tend to a great depth and the cartilaginous softening, likewise, 
is moderate in amount. A discoloration of the cement is met 
with only in exceptional cases when, in consequence of resorp- 
tion, it remains projecting from the margin of the carious cavity. 
The dentinal substance within the carious locality sometimes 
presents a gray cloudiness from the accumulation of finely-di- 
vided fat, which may be demonstrated by the application of hy- 
drochloric acid. Grains of leptothrix occasionally proliferate 
in large numbers within the perforated dentine. 

Caries of the different kinds of Teeth. — As a general 
rule, caries originates in the external depressions of the teeth, 
which afford localities for the accumulation of foreign matter, 
the removal of which is difficult or utterly impossible. The 
localities primarily affected comprise chiefly the longitudinal 
and transverse grooves upon the masticating surfaces of the 
bicuspids and molars, the contiguous surfaces of crowded teeth, 
all the deep and manifold indentations and grooves which occur 
upon surfaces that are smooth normally and are occasioned by 
malformations of the enamel, and, finally, all surfaces which are 
repeatedly or constantly brought into contact with the labial or 
buccal mucous membrane or the secretion of the gums, as the 
facial surfaces of the necks of the teeth. The surfaces directed 
towards the cavity of the mouth nearly always remain unaffected 
by caries, since foreign matters adhere to them only with dif- 
ficulty, being readily removed by the movements of the tongue, 
except in those cases where there are depressions from defects 
in the enamel. Caries seldom originates upon the contiguous 



394 ANOMALIES OF THE SECRETIONS. 

surfaces of teeth which are separated by slight intervals from 
each other, or stand alone in consequence of the detachment or 
extraction of the adjacent teeth. 

Permanent Teeth. — The labial surfaces of transversely- 
grooved upper central incisors are liable to be attacked. A 
uniformly dirty-yellow spot, corresponding to the locality of the 
transverse groove, is observed at first. If a breach of substance 
has occurred, there is found a transverse oval depression. If 
the facial surfaces, especially in the lower segments, present a 
number of depressions, these, particularly the larger ones, are 
very liable to become the seat of caries. The medial, contiguous 
surfaces of both teeth, when the crowns are closely approximated 
or overlap, are attacked in the vicinity of the incisive edges. 
The lateral (distal) surfaces are more frequently the subjects of 
the disease, particularly if the lateral incisor has an oblique 
position and the contact of the surfaces of the lateral and cen- 
tral incisors respectively is more extensive and closer than is 
the case ordinarily. The crowns of these teeth, at the carious 
localities, present hemispherical excavations which, facing each 
other, form a roundish cavity. The facial surfaces of the necks 
of the upper central incisors not infrequently are the seat of 
extensive caries. The lingual surfaces are affected only when 
an infundibuliform depression between two folds of enamel 
(comp. p. 33) or transversely-disposed indentations are present. 

The not infrequently displaced and distorted upper lateral 
incisors are very likely to become affected with caries, the 
liability being increased by the multiplication of the points of 
contact with the adjacent teeth. The surfaces which come into 
contact with the contiguous teeth or the facial surfaces of the 
necks are most frequently the seat of the origin of caries. We 
have also seen cases where the disease arose in connection with 
transverse grooves upon the facial surface, and with indentations 
or an infundibuliform depression upon the lingual surface. 

The upper canines are affected primarily upon the facial sur- 
face of the necks and less frequently upon the surfaces in rela- 
tion with the adjacent teeth, which usually are previously 
affected with caries ; the facial surfaces of the crowns are at- 



CARIES OF THE DIFFERENT KINDS OF TEETH. 395 

tacked only when they present depressions and grooves in the 
enamel.* 

The upper bicuspids are invaded in the depressions upon the 
masticating surface, more frequently upon the surfaces which 
come into contact with the adjacent teeth, and upon the buccal 
surfaces of the necks. 

In the first upper molars, the disease very frequently makes 
its appearance in the depressions formed by the branching 
grooves and very commonly at several points simultaneously, 
if the abnormally developed enamel contains numerous depres- 
sions and grooves. The masticating surfaces of the second and 
third molars are less frequently the seat of primary caries than 
those of the first molars. The buccal surfaces of the wisdom 
teeth, in consequence of their close contact with the mucous 
membrane of the cheeks, are quite liable to become affected. 
Frequently the molars are attacked upon their surfaces of con- 
tact, and upon their necks when the teeth are worn down upon 
their masticating surfaces, while there may be no perceptible 
affection of any other portion of the crown. 

The lower incisors are attacked upon their surfaces of contact, 
upon the surfaces of the necks and those of the crowns presenting 
depressions in the enamel, and upon the surfaces of slightly 
overlapping and displaced teeth, which come into immediate 
contact. 

The disease makes its appearance in the lower canines, gener- 
ally in consequence of contact with carious portions of adjacent 
teeth, upon the surfaces of contact and upon the facial portions 
of the necks. 

The primary affection of the lower bicuspids occurs in the de- 
pressions upon their summits, frequently upon the surfaces of 
contact, especially when there is a displacement, and upon the 
facial surfaces of the necks. 

The lower molars become affected at the points of intersection 

* In this country, caries of the upper canines occurs most frequently upon 
their proximate surfaces, the facial surfaces of their necks seldom being dis- 
eased. In the tables of Mr. Tomes, in fifty-eight extractions of 'canines from 
the upper jaw, nine were carious upon their proximate surfaces and but one 
on the facial surface. — T. B. H. 



396 ANOMALIES OF THE SECRETIONS. 

of the grooves, at the points of divergence of the lateral grooves, 
frequently upon the surfaces of contact and, sometimes, upon 
the facial surfaces of the necks. The wisdom teeth, particularly, 
and the first molars, in consequence of the frequent occurrence 
of anomalies in the development of the enamel, are attacked in 
more than one place. 

Carious Roots of Permanent Teeth. — One would be astonished 
at the large number of carious roots which may be found by ex- 
aminations, post mortem, a fact to be accounted for by the gross 
neglect of the teeth, particularly among the lower classes of peo- 
ple. The roots of the molars rank first; these are excavated, 
present sharp edges and points and, sometimes, the remains of 
enamel. In consequence of the frequent occurrence of alveolar 
abscesses, the carious roots become deprived in part of their 
support, particularly upon the facial wall of the upper jaw, and 
it is not uncommon for them to become twisted slightly and in- 
clined to a considerable degree towards the face; in some cases, 
the alveoli are destroyed almost entirely by suppuration, and 
the roots occupy a nearly horizontal position, attached to the 
closed terminal portions of the alveoli by means of the thickened 
root-membrane. In consequence of suppuration of the alveoli, 
the carious roots of the lower molars acquire a marked inclina- 
tion anteriorly. 

Carious roots of teeth which have but one root generally re- 
tain their normal positions, but sometimes acquire a facial or 
lingual inclination, particularly if they are employed in chewing 
during the progress of chronic caries, which fact will be indi- 
cated by the surfaces, grooves, and step-like breaks produced by 
chewing. It is self-evident that abraded surfaces of this descrip- 
tion can only be produced when several of the neighboring teeth 
are wanting, or merely their roots remain. 

Milk Teeth. — In consequence of their less compact character 
(Thomson, of Glasgow, found less than thirty-seven per cent, 
of organic matter in the milk teeth), the thinness of their enamel 
layers and the profuse secretion from the gums and glands of 
the oral cavity, caries has a more acute course in the temporary 
teeth. The molars are attacked most frequently; their crowns 
are destroyed to a considerable extent, the carious cavities are 



FREQUENCY OF CARIES. 397 

comparatively large ; the dentine frequently is studded with 
several light-brown spots ; a considerable portion of the thin 
enamel, of the incisors especially, becomes detached quite easily, 
leaving the light-brownish discolored, and superficially softened 
dentine exposed. If the caries has a very acute course, it in- 
volves the entire circumference of the crown which, finally, is 
destroyed. The disease attacks, primarily, the depressions and 
grooves upon the masticating surfaces of the molars, the facial 
surfaces of the necks and the surfaces of contact with adjacent 
teeth. The extension of the disease from a carious tooth to its 
sound neighbor (infection) takes place quite rapidly ; it is not 
uncommon to find most of the teeth in a jaw affected. 

Frequency of Caries. — Magitot* tabulated a series of cases, 
ten thousand in number, showing the relative frequency of caries 
in the different kinds of permanent teeth. Taking all the cases 
into consideration, it appears, he says, that the relative fre- 
quency of caries in the upper and lower teeth respectively, is in 
the proportion of 3 : 2. This proportion, however, is not appli- 
cable to the molars, since the first aud second lower molars are 
affected more frequently than the corresponding teeth of the 
upper jaw. From his tables, however, this result may be stated 
more in detail, as follows : The quotients, expressing the ratio 
of frequency, presented by the several kinds of teeth in the 
upper and lower jaw respectively, are in round numbers, 20 for 
the central and 24 for the lateral incisors, 6 for the canines, 2.5 
for the first, and 1.6 for the second bicuspids, 0.8 for the first, 
0.6 for the second, and 1.5 for the third molars; that is to say, 
the upper central incisors are affected twenty times as often as 
the corresponding teeth of the lower jaw, and so on. No im- 
portant difference is observed between the teeth on the right 
and left side respectively. According to Magitot's tables, the 
different kinds of teeth present the following order, in respect 
of the frequency of their affection with caries, beginning with 
those most frequently affected: lower first molar, upper first 
molar, lower second molar, upper first bicuspid, upper second 
bicuspid, upper lateral incisor, upper second molar, upper cen- 

* Op. cit., p. 48. 



398 



ANOMALIES OF THE SECRETIONS. 



tr&l incisor, lower second bicuspid, upper canine, lower first 
bicuspid, upper wisdom tooth, lower wisdom tooth, the two lower 
incisors. The scale drawn up by Hasler Harris* corresponds 
very nearly with this.f 



* Quart. Jour, of Dental Science, 1857. 

f The following is the table by Dr. E. Magitot, referred to in the text 



Central Incisors, 



Lateral Incisors, 



642 



77 



Superior, 



f bu 
jln 



Canines, 515 



fSu 
,310 \ 

(In 

rSu 

tin 

{Superior 
Inferior, 



1st Bicuspids, .... 

2d Bicuspids, 1,310 



iferior, . 

{Superior, . 
Inferior, . 
Superior, . 
Inferior, . 
Superior, . 
ferior, . 
Superior, . 
ferior, . 
Superior, . 



2d Molars, 1,7: 



3d Molars, 3G0 



( Superior, . 
( Inferior, . 

{Superior, . 
Inferior, . 



Total,. 

Superior, 
Inferior, 



10,000 

6004 
3996 



J Bight, 

\Left, . 
r Right, 
1 Left, . 

747 J Ri ? ht » 
r47 - | Left, . 

Right, 

Left, 



612 
30 



30 



.., r Right, 
440 { Left, . 
- n r Right, 
\ Left, . 
r Right, 



-o 



940 \ Left,. 
Right, 



500 



Left, 



1 540 / Ki - ht ' 
1)040 \Left, . 

l » 810 \JLeft, . 

fan / Richt, 
690 { Left, . 

1)040 \Left, . 
290 / Ki-ht. 
~ u 1 Left, . 

«•{££: 



10,000 



f Right side face, 
\ Left, •• 



4701 



304 

308 

20 

10 

369 

378 

20 

10 

198 

247 

20 

50 

345 

595 

170 

400 
410 
270 
230 
728 
812 
910 

380 
310 

549 
100 

120 

80 



10,000 



This table differs in several respects from one prepared by me, from records 
of filling and extractions of permament teeth in twenty thousand cases. 
Though this includes extractions from all causes, yet the percentage removed 
for other diseases than caries is so small, that the tables are worthy of com- 
parison. T. B. H. 



FREQUENCY OF CARIES. 



399 



With regard to the sex, according to Magitot's enumeration, 
the ratio of 3 : 2 expresses the relative frequency of caries of the 
teeth in females as compared with the same in males. Harris 
asserts that with females caries occurs nearly three times as 
often as it does with males. The period of pregnancy, as is 
well known, is especially favorable to the development of caries. 

With regard to the age, caries is most frequent between the 
tenth and twentieth year of life. Later in life (about the fiftieth 
year), it is not uncommon for another period to occur in which 
teeth, previously sound, are destroyed by caries within a short 
time. Magitot drew up some instructive tables in detail, show- 
ing the age at which the several corresponding teeth in both 
jaws were affected. With regard to the milk teeth, he ascer- 



Central Incisors, . 



Lateral Incisors, 



, 2,189 

. 1,954 

Canines, 1,261 

1st Bicuspids, .... 2,073 

2d Biscuspids, .... 2,585 

1st Molars, 4,499 

2d Molars, 3,615 

3d Molars, 1,924 



{Superior, . 
Inferior, . 
{Superior, . 
Inferior, . 
Superior, . 
Inferior, . 

{Superior, . 
Inferior, . 
{Superior, . 
Inferior, . 
(Superior, . 
Inferior, . 
Superior, . 
Inferior, . 
Superior, . 
Inferior, . 



2,101 | 



Total, . . 

Superior, . . 
Inferior, . . 



20,000 

13,136 

6,864 Left 



13,136 f Eight 



1,827 

127 
1,058 

203 
1,588 

485 
1,715 

870 
2,273 
2,126 
1,675 
1,940 

899 
1,025 

20,000 
side face, 



Right, 
Left, 
Right, 
Left, 
Right, 
Left, 
/ Right, 
\ Left, 
f Eight, 
\ Left, 
Eight, 
Left, 
r Eight, 
\ Left, 
I Right, 
\ Left, 
/ Eight, 
X Left, 
/ Right, 
\ Left, 
Eight, 
Left, 
/ Right, 
\ Left, 
/Eight, 
\ Left, 
f Eight, 
X Left, 
Eight, 
Left, 
Risht, 
Left, 



1,058 

1,043 

37 

51 

939 

888 

68 

59 

504 

554 

101 

102 

767 

821 

264 

221 

906 

809 

467 

403 

1,189 

1,084 

1,092 

1,034 

838 

837 

938 

1,002 

470 

429 

513 

512 

20,000 



10,151 

9,849 



400 ANOMALIES OF THE SECRETIONS. 

tained that caries may be observed as early as the third and 
fourth year, and that its frequency increases in regular progres- 
sion from this period up to the twelfth year, the period at which, 
on the average, the last milk tooth becomes detached. 

In respect of race, notable differences are observed. Broca, 
and more particularly Mummery, carefully examined large col- 
lections of skulls, for the purpose of ascertaining the frequency 
of dental caries. The latter found a percentage of 41.66 as ex- 
pressing the frequency of caries among those of the ancient 
Egyptians, 2.94 among those of the ancient Britons with elon- 
gated skulls, 21.87 among those with round skulls, 28.67 among 
those of the Romano-Britons, 15.78 anions those of the Anglo- 
Saxons. Among the modern races, he obtained the lowest per- 
centage from those of the Esquimaux, natives of the northern 
coasts of America, New Zealanders, and inhabitants of the 
northern parts of the East Indies. In Europe, the results show 
a percentage in favor of the Sclavonic race. 

In connection with the peculiarities in the structure of the 
teeth according to race may be considered those which are 
manifested according to family. It is a familiar fact to all 
dentists, that children's teeth very frequently resemble those of 
the father or mother and, therefore, that many defects and mal- 
formations of the teeth are hereditary in a family, e. g., the ab- 
sence of the upper lateral incisor, the oblique position of a certain 
tooth, the shape of the teeth, spots upon them, &c In the same 
way, also, is the familiar and curious fact to be explained, that 
with children of the same family the corresponding teeth become 
carious in the same order, at similar points and at a certain age. 

Many are inclined to ascribe the differences in respect of the 
frequency of caries, to locality and the articles of diet. Climatic 
and geological peculiarities, or the water, are assigned as the 
causes, though authoritative grounds cannot be adduced in sup- 
port of these views. Mummery endeavored to establish a par- 
allel between the ordinary food of the different races and the per- 
centage illustrating the frequency of caries, but definite results 
cannot be drawn from these data. As a matter of course, ade- 
quate nutritive material is just as requisite for the formation 
and maintenance of the teeth as it is for the rest of the body. 



FREQUENCY OF CARIES. 401 

whether it be of an animal or vegetable nature. If it be true 
that geological and climatic conditions, and the means of sub- 
sistence which are connected with the same, have such a pre- 
ponderating influence in respect of the frequency of caries, then 
it is impossible to explain the fact that foreigners belonging to 
different races, who are exposed to the same conditions with the 
native inhabitants, still retain the typical structure of their teeth 
as well as that of their bodies, and continue to furnish the pro- 
portion of dental caries peculiar to their race. This is found to 
be the case with the isolated Sclavonic races of Austria and the 
descendants of the Celtic race in France.* 

Popular customs promote or retard and may even give rise 
to caries. Steinbergerf remarks, in this connection, that the 
crowns of the upper milk incisors, especially in children of the 
lower classes, are mostly or entirely destroyed by caries even 
in the second or third year of life, while the lower incisors are 
scarcely ever so extensively affected and the molars, usually, are 
still entirely sound. It is found in such cases that the children 
have been accustomed for months and even years to use a suck- 
ing-bag containing cracker or white bread which is first soaked 
in milk and then in a weak solution of sugar. In this way, he 
says, all the conditions necessary for the rapid formation of 
vinegar are afforded ; the sugar acts during the process of its 
fermentation, and the action of acid in statu nascenti is much 
more intense. 

Tobacco-smoke or juice is considered by many to be a pre- 
servative, or a means of preventing caries, though it is not stated 
whether the secretion of the gums acquires an alkaline condition 
or the proliferation of leptothrix is diminished. On the other 
hand, it is quite common to find teeth with a sooty covering, 

* As geological, climatic, and social conditions exercise a predominant 
influence upon the growth and development of the various races mentally 
as well as physically, it is evident that the development of the dental organs 
cannot fail to be controlled by the same causes. In this country, which is 
annually receiving large numbers of foreigners by emigration, the typical 
traces of race are usually effaced after the lapse of a generation or two, the 
descendants possessing all the peculiarities, and their teeth apparently being 
as liable to caries as the teeth of Americans generally. — T. B. H. 

f Deutsche Viertelj. f. Zahnh. ; 18G2. 

26 



402 ANOMALIES OF THE SECRETIONS. 

from tobacco-smoke, upon the lingual surface and, at the same 
time, an extensive carious affection of the facial surface of the 
neck. 

An enumeration has been made of the articles of diet which 
are said to tend to increase the frequency of caries, such as 
fruit, food which has become sour, curdled milk ; but sugar is 
regarded as the most injurious. Larrey* asserted that teeth 
are acted upon by a solution of sugar, the enamel acquiring an 
opaque appearance, the tooth readily crumbling and becoming 
almost gelatinous. In this connection, stress is laid upon the 
affinity of the sugar for the lime with which it enters into com- 
bination. Marchand denied the accuracy of .these experiments, 
and asserted that no perceptible changes can be detected in 
teeth which have lain for weeks in a solution of sugar. It has 
also been stated by English writers that the natives of the East 
Indies eat a large amount of sugar and with a mere vegetable 
diet have very good teeth ; to be sure, they keep their teeth 
very clean. Magitot recently experimented with sugar and ob- 
tained a result corresponding with that of A. Westcott (1843 . 
namely, that sugar exercises no direct, i. e., in the condition of 
sugar, injurious effect upon the teeth, since solutions of sugar 
occasioned extensive destruction of the tooth only after some 
time (two years) had elapsed, when the solutions were left alone 
or materials were added to them which acted the part of ferments. 
The fermentative process gives rise to the development of lactic 
acid and, subsequently, butyric acid and a few of its derivat: 
as propionic and valeric acids, &c. Mantegazza, of Pavia, ex- 
perimented in another way; he placed teeth, which had pre- 
viously been dried and weighed, in solutions of sugar of various 
degrees of concentration, in distilled water and in saliva which 
was removed directly from the mouth, and, after a few days, 
noticed an acid reaction of the fluid which contained traces of 
lime; the teeth had lost in weight. His conclusions coincide 
pretty nearly with those of Magitot. 

Various occupations are directly or indirectly injurious. It 
is a well-known fact that the teeth of confectioners and cooks 

* Gaz. Med. di Milano. 1844. 



EFFECTS OF CARIOUS TEETH ON THE BODY. 403 

are very apt to be affected, and it is supposed that the dust from 
the sugar enters into combination with the mucus of the gums 
and the deposits on the teeth, and occasions an acid fermentation. 
Richardson calls attention, in his lectures, to the fact that dental 
caries is exceedingly common among the fur-dyers, since the 
teeth are acted upon by the fumes of the nitric acid which is 
employed for cleansing and imparting a yellow color to the furs. 
The fumes produce a dryness and irritated condition of the oral 
mucous membrane of the tongue and fauces ; as a rule there is 
constipation, pain in the occipital region and a sensation of 
constriction of the chest. The drying-room, in which are placed 
the damp skins impregnated with the nitric acid, is filled with 
the fumes of this acid. The teeth lose their enamel and, occa- 
sionally, are entirely destroyed. The fumes of ammonia, also, 
and the dust occasioned by beating the dried skins, exercise an 
injurious action. 

Many diseases of the general system promote the development 
of caries, especially those during the existence of which the 
mixed saliva generally acquires an acid reaction, including 
many forms of dyspepsia, cancer of the stomach, diabetes, 
scrofula, rachitis, phthisis, and aphthae. 

Effects of Carious Teeth upon the Rest of the Body. — 
Although, in many cases, it is hardly possible to decide abso- 
lutely whether the caries is the result or the cause of a certain 
affection, still approximate results may be obtained from the 
observation of cases in which a healthy condition is restored 
after the removal of carious teeth. Every dentist has oppor- 
tunities enough for observing cases of this kind. 

The effects are manifested in adjacent or more distant organs 
with which the mixed saliva comes into contact. The sharp 
edges of carious teeth sometimes give rise to ulcerations having 
a cancerous appearance upon the oral mucous membrane, the 
tongue, or lips, a fact readily explained since the wounded parts 
are constantly exposed to the foul products of decomposition, 
resulting from the carious disease. Liston ascribed a number 
of local and general affections to the presence of carious teeth 
or decomposed fragments of teeth. The consecutive inflamma- 
tions of the pulp, root-membrane, gums and periosteum, the ab- 



404 



ANOMALIES OF THE SECRETIONS, 



scesses in the alveoli and jaws, have been considered in the pre- 
ceding pages. Liston also considers caries of the teeth to be a 
frequent cause of swelling of the tonsils, intense and long-con- 
tinued headache, various digestive derangements and gastralgias, 
which affections disappear as soon as the offending carious teeth 
are removed. 

Caries of Reinserted Human Teeth. — As a rule, the 
necks of these, and especially of the front teeth of the upper 
jaw, become the seat of the disease which generally affects their 
entire circumference. This fact is easily explained when we 
consider that the gum does not become attached to the neck, 
and hence accumulations of the secretions oecur more readily. 
The dentine in the above locality acquires a dirty-yellow, 
brownish- yellow, dirty-brown discoloration and undergoes a 
superficial cartilaginous softening which spreads beneath the 
enamel-layer adjacent to the neck, and the enamel acquires an 
eroded appearance. 

The deposits of pigment, consequent upon the carious pro- 
cess, may be traced to a depth of 
1 to 2 millimetres into the dentine: 
adjacent to the pigmented portion 
occurs a dark zone which adjoins 
another, in many cases, very light 
zone. Upon close examination of 
the dark zone and its transition into 
the pigmental and light port: 
respectively, the same changes are 
found as in ordinary caries of the 
teeth. The canals are filled with 
rows of minute grains which gen- 
erally have a roundish, in some 



Fig. 101.* 




* Fig. 101 illustrates a carious affection of the dentine of a reinserted 
human incisor. The portion of dentine examined still retained sufficient 
consistence to allow a thin and polished section to be prepared. At the upper 
surface (a) are sharply denned cavities; these were tilled with masses of lep- 
tothrix which have fallen out. Next in order is a granular, cloudy portion 
where the canals, which are more clearly visible beyond (b), are filled with 
grains arranged in rows like strings of pearls. The interglobular spa 
are clouded by accumulations of dirty-brownish molecules. Magnified 500 
diameters. 



CARIES OF REINSERTED HUMAN TEETH, 



405 



cases, an elongated, rod-like shape, are very clearly distinguish- 
able from the intermediate substance and, when they are of 
larger size, form chains like strings of pearls (Fig. 101). If the 
calcareous salts be removed from dentine of this description, by 
means of hydrochloric acid, and heat be applied until the pro- 
cesses of the dentinal cells are set free, knotty swellings make 
their appearance upon them, in precisely the same manner as in 
ordinary carious dentine. The processes, here and there, are 
beset with grains of leptothrix ; quite a large portion of the 
granular mass in the canals and clouded intertubular tissue, how- 
ever, is composed of fat, as is shown by the fact that it forms a 
large number of drops on the addition of hydrochloric acid. 
The interglobular masses are light in some places ; in others they 
present a molecular cloudiness and, sometimes, a dirty-brownish 
discoloration. 

The outer surface of the softened, cartilaginous dentine pre- 
sents very distinct perforations which ex- 
tend to a considerable depth into its sub- 
stance. These form the chief abode of 
the masses of leptothrix which occupy 
the manifold excavations and may be 
traced in the irregular pouches which 
dip down deeply along the course of the 
dentinal, canals (Fig. 102). The den- 
tinal fibres, beset with an abundance of 
grains of leptothrix, form free projections 
beyond the borders of the section, when 
there is a marked degree of cartilaginous 
softening, and in cross-sections display, 
here and there, a notable thickening. A 
violet color may readily be imparted to the 
leptothrix mass by means of iodine and 
hydrochloric acid. 



Fig. 102.* 




* Fig. 102 shows softened, cartilaginous, carious dentine, from a reinserted 
human tooth. Proliferations of leptothrix-rnatrix have taken place from 
irregular, pouch-like excavations into the dentine, along the course of the 
canals. Magnified 500 diameters. 



406 ANOMALIES OF THE SECRETIONS. 

In addition to the above, mycelium tubes, similar to those of 
oidium albicans, are met with, sometimes, upon the surface of 
the decomposed dentine. 

Caries, as is well known, frequently makes rapid progress in 
the dentine of reinserted teeth. I observed a case where, in 
fourteen days after the insertion of a pivoted tooth, the dentine 
in the vicinity of the pivot was found to have acquired a deep 
black color, to the depth of about one-third of a millimetre. 
Brown and light spots pervaded the dentine. 

The eroded border of the enamel presents cup-shaped exca- 
vations and numerous cracks which extend in short segments 
along the undulatory courses of the enamel. fibres, or form a 
network. In the vicinity of the affected portions, the enamel 
has a mottled, clouded appearance, the prisms have a dark or 
black-brown color, with a reddish tinge, now and then, and are 
in the process of disintegration. 

Caries of Teeth made of Ivory from the Hippopotamus. 
— Thomson calculated the specific gravity of this ivory to be 
1.866, and the amount of its organic substance to be 33.41 per 
cent. The caries, which frequently is very extensive, does not 
confine itself to the artificial teeth, but spreads beyond the 
groove which serves for the'reception of the alveolar arch. The 
discolorations are very marked, being sometimes light-colored, 
at other times, dark-brown ; the cartilaginous softening is so 
extensive that sections may readily be made. The loss of sub- 
stance may be quite considerable, both upon the necks and lat- 
eral portions of the crowns, and hemispherical defects, sometimes, 
are formed upon adjacent teeth, in the same manner as in natural 
teeth; it is obvious, therefore, that the carious process spreads 
from one artificial tooth to its neighbor. Caries generally com- 
mences upon the facial and lingual surfaces, and upon the mo- 
lars ; it originates in the grooves where it forms irregular exca- 
vations and, also, in the vicinity of cracks in the dentine and 
about those portions where pivots have been inserted, or plates 
have been adapted. 

The yellow, light, or dark-brown pigmental degeneration com- 
mences upon the carious surface and extends into the dentine to 
a depth of a few millimetres. Next to this portion are dark 



EXPERIMENTS UPON TEETH. 407 

and light zones and, beyond the latter, the contents of the den- 
tinal canals present transverse breaks, in many places. Some- 
times the dentinal fibres or processes of the dentinal cells dis- 
play such uniform transverse fissures that one might imagine 
them to be thallus-threads, composed of minute articulations ; 
in other places, however, the irregularity of the clefts does not 
admit of such an interpretation. The manner in which the met- 
amorphosis in the dentinal canals within the dark and pigmental 
zone takes place is quite evident. Minute, sometimes glittering 
grains, arranged closely together in rows and following the di- 
rection of the canals, and, towards the outer surface, rod-like 
bodies, isomorphous with Bacteria, are inclosed in the canals. 
Sections, which have been decalcified and heated until the isola- 
tion of the dentinal fibres has been effected, establish the fact 
beyond any doubt that a fatty degeneration has ensued in the 
affected dentine and that a proliferation of leptothrix has taken 
place within the canals. The dentinal fibres, frequently thick- 
ened to five and ten times their normal size and presenting 
varicous swellings, are beset with grains of leptothrix. A violet 
color is produced by the latter in the dentinal canals, on the 
addition of iodine and acid to thin sections. 

Sections of the softened, cartilaginous dentine, made in a di- 
rection perpendicular to that of the canals, present appearances 
exactly similar to those found in carious reinserted human teeth 
or in ordinary caries of normal teeth, i. e., we find, besides the 
normal canals which are considerably thickened, have a glitter- 
ing appearance and are surrounded by a light halo, groups of 
others, inclosing, sometimes, a finely-granular mass, the con- 
tents of which assume a more or less distinct violet color on the 
addition of a solution of iodine and acids. 

In artificial teeth in which the dentinal canals have a direction 
parallel to that of the carious surface, caries extends into the 
substance, independent of the course of the dentinal canals. 

Experiments upon the Teeth with various Substances. 
— A. Westcott (1843) and Allport (1858) made special investi- 
gations in order to determine the effects of acids and other sub- 
stances upon the teeth. Their results coincided in showing that 
mineral and vegetable acids affect the enamel in such a way that 



408 ANOMALIES OF THE SECRETIONS. 

it may easily be scraped off. The former, also, ascertained that 
sal'ts, whose acids have a stronger affinity for lime than for their 
own bases, likewise act upon the teeth ; that vegetable substances 
only act when they undergo acetous fermentation, as sugar, for 
example, and that the action of animal substances is very slow, 
if, indeed, they exert any action, even in association with very 
advanced decomposition.* 

Magitot submitted teeth to the action of acids, salts and al- 
bumen, during certain, quite long intervals (up to two years), 
and asserts that he produced conditions analogous to caries. 
He obtained positive results with lactic acid in the proportion of 
1 : 100 parts of water. The teeth were allowed to remain in this 
fluid for two years, when it was found that their roots had 
become flexible, gelatinous, as it were, and shorter; the enamel 
was chalky, friable, separated from the coronal surface in places 
and readily reducible to a white powder by trituration. The 
whole dental mass presented a general brownish color. Teeth 
which were covered with resin, with the exception of one portion, 
became affected with penetrating caries, in some cases to a depth 
of 3 to 4 millimetres. A solution composed of a gramme of lactic 
acid to a litre of water made no perceptible effect upon teeth 
which were kept immersed in it for two years. 

According to his experiments, butyric acid produces very 
nearly the same effects as lactic acid ; the color produced by 
the caries, also, is analogous. It is a fixed acid not susceptible 
of fermentation. 

With citric acid, also, there was no indication of fermentation, 
and he found its deleterious action to be quite intense, so that, 
at the expiration of two months, it was quite marked even with 
a solution of 1 : 1000 parts of water. He states that this acid 
is more injurious than any others which act upon the teeth. It 
occasions no discoloration, which leads to the conclusion that it 
naturally induces a white caries. 

From experiments with malic acid and cider, he found that 
the former, in the proportion of 1 : 100 parts of water, acts with 
more energy than the latter. 

* Leber und Eottonstein iiber Caries, p. 6S. 



EXPERIMENTS UPON TEETH. 409 

Magitot repeated the experiments of Berzelius and Dumas, of 
decalcifying teeth by subjecting them to the action of carbonic 
acid, as it occurs in Seltzer water which, usually, contains one 
volume of water to five volumes of gas. The enamel became 
friable, the dentine became softened. When equal volumes of 
water and gas were employed, he was unable to detect any 
change in the teeth wh\ch were immersed in the solution during 
eight days. For reasons which may readily be understood, he 
is of the opinion that acidulated waters do not act upon the 
teeth. 

Teeth which were allowed to remain in fluid containing fer- 
menting albuminoid substances acquired a general and uni- 
formly softened condition in the course of two years ; the roots 
became transparent and soft, the enamel friable and opaque. 
Teeth which were protected entirely, excepting at one point, 
presented the characters of true caries at the exposed part. 
During the putrefaction, fatty acids formed, of the acetic and 
benzoic series ; the putrid odor suggested butyric and valerianic 
acids. 

A solution of alum (1 : 100 parts of water), which at the 
end of two years had an acid reaction, had not affected the roots 
in the least during this period, while the enamel lost its glazed 
appearance, became opaque and had the appearance and brittle- 
ness of a layer of chalk ; the dentine and the cement were not 
in the least affected. 

The action of a solution of binoxalate of potash (1 : 100 parts 
of water) was very similar to that of the solution of alum, that 
is, it was limited to the enamel. 

Acetic acid (1 : 100 parts of water) induced a very peculiar 
change in teeth which were allowed to remain in it for two years. 
The roots became softened throughout, flexible, yellowish and 
considerably thinner, while the coronal portions remained unaf- 
fected. The enamel retained its polished appearance and firm- 
ness. 

Tartrate and bitartrate of potash (1 : 100 parts of water), also, 
left the enamel intact and attacked the cement and dentine, but 
their action penetrated to a less depth than that of acetic acid. 

A solution of chloride of sodium (1 : 100 parts of water), con- 



410 ANOiMALIES OF THE SECRETIONS. 

taining a few drops of creasote, manifested no action upon the 
teefeh. 

Tannin (1 : 100 parts of water) acted upon the cement and 
dentine, but not in the least upon the enamel. 

Magitot divided the substances, according to his experiments, 
into four groups : 1. Those which attack all the dental sub- 
stances; 2. Those which occasion a disorganization of the enamel 
exclusively ; 3. Those which act exclusively upon the dentine 
and cement ; 4. Those which induce no change in either of the 
three dental tissues. 

Unfortunately, Magitot neglected to make histological exam- 
inations of the teeth in which caries was induced artificially, as 
this would be necessary in order to establish the identity between 
natural and artificial caries. 

Leber and Rottenstein repeated a number of Magitot's ex- 
periments, with these modifications, however, that they dimin- 
ished the duration of the action and, as it appears, allowed the 
substances to act only upon the entire surfaces of the teeth and 
not upon separate portions. They took exception to the ex- 
periments of Magitot and showed that the results are not due 
to the acids alone, but, also, to the decomposition of the organic 
substance of the tooth, to putrefaction and fermentation, and 
that the effects produced by the low vegetable and animal organ- 
isms which are developed in the latter processes, also, are to be 
taken into account. They were unable to satisfy themselves 
that the mere action of acids produces changes exactly similar to 
those observed in caries. Their experiments with tartaric and 
acetic acids, oxalic acid and alum gave results different from 
those reported by Magitot in regard to the non-affection of the 
enamel and cement respectively. 

Caries of the Teeth of Animals. — I have had an oppor- 
tunity of examining only a few carious teeth from the horse, 
which were furnished to me by Prof. F. Miiller. As is well 
known, caries of the teeth is a very rare occurrence with ani- 
mals. They were cases of so-called dry, chronic caries, with no 
evident, separable, cartilage-like, softened layers in the dentine 
or cement. 

In one premolar, the carious affection was presented in its 



CARIES OF THE TEETH OP ANIMALS. 411 

early stage, in the form of a blackish-brown, circumscribed spot, 
the size of a lentil, upon the much worn, excavated, grinding 
surface, and made its first appearance on the prominent fold of 
enamel. The carious pigmental degeneration extended, in many 
places, through the entire thickness of the enamel, as far as the 
line of junction with the dentine, and, in well-marked localities, 
was indicated by an intense sap-brown color, the line of demar- 
cation being well defined. The enamel prisms appeared to be 
filled with a molecular mass which I did not consider to be lep- 
tothrix, since the surface of the enamel was found to be smooth, 
and without any deposit upon it. 

Where the caries was more extensive, in the tray-shaped 
abraded, grinding surface, and involved, also, the bony and den- 
tinal tissues, the encroachment of the affection upon the den- 
tine was so slight that cross-sections presented merely a narrow 
streak of carious, blackish-brown discoloration. No finely 
granular contents were visible in the dentinal canals adjacent 
to the affected portions, and no leptothrix-mass was attached to 
the latter. 

The strong bony tissue of the premolar became undermined by 
the carious process in such a manner, that carious cavities were 
met with at a considerable depth below the grinding surface. 
Here, also, the light-brown discoloration involved only a few rows 
of bone-corpuscles which, together with the interglobular sub- 
stance, were uniformly pervaded. 

The exterior of the carious bony tissue of the tooth was free 
from leptothrix; the peripheral layers of the latter tissue, as 
well as of the carious dentine, had a more homogeneous, trans- 
parent appearance; it is still undecided if it be allowable to re- 
gard this as a slow process of decalcification. 

Theories of Caries. — From the historical account which 
has been given, it is evident that the theory of caries has been 
sought for chiefly in three directions ; some have given promi- 
nence to the vital, others to the purely chemical and to the 
parasitic processes, and still others have advocated divers views, 
based upon various combinations of the latter processes. 

Formerly, the knowledge of the structure of the tooth was so 
defective that there was no anatomical basis for the study of 



412 ANOMALIES OF THE SECRETIONS. 

the carious process, and, until the fourth decade of the present 
century, when the histology of the tooth became determined by 
degrees, it was impossible for an accurate investigation of the 
structural changes in the carious tooth to be made. In order 
to complete our knowledge of the subject, however, a gap re- 
mained to be filled up, until within the last ten years, namely, 
the establishment of the history of the development upon a 
sound basis. As soon as these preliminary results were ob- 
tained, it became possible, with the aid of the improvements in 
optical instruments, to trace the process in its different phases. 

The writers of the earlier times, for the most part, were vi- 
talists, since they professed to recognize a life- in the tooth and 
appear to have referred the destructions attending dental caries, 
resembling, in the general appearances, the gangrene of other 
organs, to a vital process. 

As soon, however, as organic chemistry furnished the analyses 
of the tooth and secretions of the mouth, although these are still 
unsatisfactory, and explained the process of fermentation with 
its manifold products, it became necessary, in connection with 
the decalcification process in dental caries, to take into account 
the action of acids developed in the secretions or in fermenta- 
tion. Hence arose the chemical theories. 

During the past ten years, our knowledge with reference to the 
marked diffusion of parasites and their injurious effects upon the 
animal economy has gradually increased; search was made for 
such animated beings in the carious tooth ; they were found, or 
were supposed to have been found, and hence the parasitic theory 
was constructed. 

Then came the fusionists, some of whom attempted to com- 
bine the vital and the chemical theories of dental caries and 
considered the latter to be a reaction, of the nature of an inflam- 
matory process, on the part of the hard dental tissue which is 
chiefly affected, the dentine, and, at the same time, retained the 
views with regard to the agencies in the process of decalcifica- 
tion. Another class combined the effects of chemical agents 
w T ith those of parasites. Still another class endeavored to unite 
all these theories and, therefore, assumed the occurrence of 
several kinds of caries. It was admitted that the caries is de- 



THEORIES OF CARIES. 413 

pendent, in most cases, upon external agencies and extends 
from the outside towards the interior, but, on the other hand, 
it was asserted that the same process may also take place in 
the opposite direction and hence caries which is developed from 
the pulp towards the exterior was described as caries interna. 

Since we know that an interchange of material takes place 
in the dentine and cement during life, as is proved by the occur- 
rence of atrophies, hypertrophies and new-formations, and that 
the dentine possesses a degree of sensibility, we cannot reject 
absolutely the idea of a reaction on the part of both hard tissues 
against the eifects of external agents. Some authors seem to 
have had an intimation of this idea, since they were inclined to 
consider the textural changes in carious dentine as vital pro- 
cesses. 

There can be no doubt that the sensibility, sometimes increas- 
ing to actual pain, of the dentine, when deprived of its protec- 
tive covering, is a vital action, and that this becomes diminished 
when the most sensitive, the peripheral portion, is destroyed by 
an external agent. These facts, however, are by no means suf- 
ficient to enable us to draw a conclusion in favor of the reac- 
tionary power of dentine in parts which are attached by caries. 

The thickening and varicous swellings of the dentinal fibrils 
were ascribed to a vital process by J. Tomes, E. Neumann and 
H. Hertz. The former asserts that the outlines of the forma- 
tive cells are restored by the diseased condition ; E. Neumann 
goes still farther and observes a proliferation of cellular elements 
of the dentine in sections which have been colored with carmine, 
and hence establishes an analogy between dental caries and in- 
flammatory and ulcerative processes in the soft parts. Leber 
and Rottenstein merely state that, in cross-sections especially, 
the contents of the widened canals are seen to be broken up into 
rod-like segments which, sometimes, are separated by slight in- 
tervals. They did not find, nor have I succeeded in observing 
the prominent nucleiform bodies in the thickened dentinal fibrils, 
after coloring the specimen with carmine, as they were described 
and illustrated by Neumann. 

The increased transparency of the dentine around the focus 
of caries and the still problematical calcification of the dentinal 



414 ANOMALIES OF THE SECRETIONS. 

fibrils are regarded by J. Tomes as attempts on the part of na- 
ture to arrest the progress of caries. The carious dentinal cone 
is interpreted by Magitot as an evidence of a reaction on the 
part of the pulp against the agent which acts from the outside. 
This condition of irritation, he says, is manifested, on one side, by 
the production of secondary dentine and, on the other, by a 
molecular deposit in the dentinal canals which become obliter- 
ated. He, therefore, regards the latter appearance, also, as a 
vital process. 

Although it cannot be denied that the living pulp does react 
against external agencies, still the interpretations of the above- 
named writers, according to which an inflammatory process of 
the pulp manifests itself in carious dentine in the different ways 
already mentioned, are incorrect, as Leber and Rottenstein have 
shown. Carious dentine of reinserted human teeth and of arti- 
ficial teeth made from the ivory of the hippopotamus presents 
the same appearances as are found in ordinary caries, in respect 
of the pigmented, dark and light zones, the granular condition 
of the dentinal fibrils, the thickening and varicous enlargement 
of the latter. The phenomena ascribed to odontitis, therefore, 
do not really belong to it. 

Dentinal new-formations, which are developed upon the wall 
of the pulp-cavity at a point corresponding to the carious locality 
in the dentine, can be induced only by an irritation in the con- 
tiguous portion of the pulp; they are an expression of the efforts 
of nature, a reparative tissue, to compensate for the peripheral 
destruction. They are particularly frequent in connection with 
caries with a tendency to a chronic character. Numerous cases 
present no trace of such repair, although the dentine presents 
all the appearances which have been mentioned. Inflammatory 
affections of the pulp generally do not make their appearance 
until the dentine has suffered a considerable loss of substance, 
or, as is the case frequently, until the pulp is covered by a thin 
layer of dentine, merely, or a perforation into the pulp-cavity 
has occurred. There are no grounds, then, for ascribing the 
changes in the dentinal fibrils to an inflammatory irritation of 
the pulp. 

It is a familiar fact, that dead animal tissues undergo a 



THEORIES OF CARIES. 415 

marked fatty degeneration under certain circumstances. In 
pathological cases, a fatty metamorphosis of organs is frequently 
met with, and this fact has been adduced, in some cases, to prove 
that fat is formed by the transformation of protein substances. 
It is not singular, therefore, that fat may also be deposited, 
under favorable circumstances, in dead dentine ; indeed it is 
found interposed in the dentinal canals in the form of drops. 

On the other hand, there is abundant proof that fungi pene- 
trate living, dying, and dead animal tissues, and there is a 
fungus, probably belonging to Mucor, whose spores sometimes 
are found in drinking-water, and which, by proliferation in the 
dead bone and dentine, produces a considerable loss of substance. * 
This fungus has no connection with caries of the tooth and 
occurs casually in carious teeth which are kept in water. Quite 
as little is the part taken by the Protococcus dentalis, described 
by Klenke as occurring in association with a special form of 
caries, which he termed vegetative decay of the teeth (Zahn- 
verderbniss). I have met with this in a single instance ; its 
relation to dental caries has not been confirmed by any writer ; 
it is an accidental occurrence, like the Puecinia graminis in the 
favus crust. 

Leptothrix buccalis, on the contrary, occurs so frequently in 
connection with dental caries and so clearly lodges, here and 
there, in the cartilage-like, softened, decalcifying dentine, that 
Leber and Rottenstein went so far as to state that the variations 
in the course of caries must depend upon the part taken by the 
fungus proliferation in the carious process. The proliferations 
of the elements of the fungus without doubt penetrate and ex- 
pand the dentinal canals, but, according to my observations, this 
cannot occur until the decalcification of the dentine is complete, 
or, at all events, until the first stage of this process. I have 
never detected a proliferation of fungus in the deeper layers of 
the still hard, carious dentine, and, in my opinion, the death of 
a certain amount of dentine, in consequence of the action of the 
acid, is necessary before it is possible for the proliferation of 

* C. Wedl: TJeber einen im Knochen unci Zahnbein keimenden Pilz. 
Sitzungsber. der kais. Akad. d. Wiss. zu Wien, 1864. 



416 ANOMALIES OF THE SECRETIONS. 

the fungus to occur. The extension of caries, in the dentine, 
therefore, according to my view, is effected by the acid and not 
by the fungus. If the acid be neutralized by the saliva, e. </., 
on the lower incisors, caries does not occur, notwithstanding 
the presence of thick layers of leptothrix, such as are met with 
in tartar. Leptothrix has no direct connection with the origin 
of caries; previous to the formation of a carious pit on the neck 
of the tooth, I have been unable to find any deposit of leptothrix 
upon the exterior, or any rows of leptothrix-grains in the in- 
terior, of the dentine. The grains which occur in the dentinal 
canals in chronic caries are minutely-divided fat. 

The action of an acid, therefore, I consider a fundamental 
condition of the occurrence of caries in all cases where there is 
evidence of a decalcification, however slight. In other cases, 
where no evidence of the latter has been furnished (in a manner, 
indeed, not to be relied upon, as in the caries carbonacea, as it 
is termed by dentists), the chemical process is still in darkness. 

Although the action of acids is admitted, still our knowledge 
is not yet sufficient to enable us to answer the questions, whether 
one or several acids, what form of the same, how and where they 
are formed ? 

The constituents of the mixed saliva vary, not merely in dif- 
ferent persons but, also, in the same individual. Its well-known 
property of converting insoluble starch into dextrine and grape- 
sugar, which latter may enter upon an acetous fermentation in 
the presence of a ferment, was turned to account by Leber and 
Rottenstein, who concluded that the acid reaction in the oral 
cavity is due principally to the acetous fermentation of particles 
of food. If it is proper to give such prominence to the latter, 
then it will be impossible to understand why caries of the teeth 
is such a very rare occurrence with animals, which are unable 
like men to remove the particles of food that remain between 
the teeth. Many races of men, who certainly are not very 
careful in observing cleanliness of the mouth, e. g., the Esqui- 
maux and New Zealanders, furnish a very small percentage. 
In well-marked chronic caries, the remains of food manifest no 
perceptible action; in so-called central caries, also, a cartilaginous 
softening of the dentine ensues without the co-operation of the 



THEORIES OF CARIES. 417 

remains of food. With many derangements of the intestinal 
tract an acid or saline taste is observed, entirely independent 
of the food. Acid sputa, increased acidity of the vaginal or 
vesical mucous membrane attest that mucous membranes of 
themselves may furnish an abnormal acid secretion. 

Magitot considers the saliva to be the active agent in the 
production of caries, when the former becomes the vehicle of 
acid substances. Leber and Rottenstein state that, if it is true 
that fungi play any part in the acetous fermentation within the 
oral cavity, a point, however, which remains to be proved, they 
are inclined to ascribe the action to leptothrix, and assert in 
common with Oehl, that in all probability lactic acid is formed 
in the acetous fermentation. Spence Bate* holds the view, that 
in consequence of a decomposition of the dentinal fibrils within 
the tubes, carbonic acid is set free ; the latter in statu nascenti, 
is brought into contact with the calcareous salts of the tissue, 
which then become decomposed with the development of acid. 
The acid which is set free, he says, is phosphoric and not lactic 
acid. 

In my opinion, especial consideration is claimed by the secre- 
tion of the gums, which comes into immediate contact with, and 
forms a partial viscid covering of the teeth. It is found, often- 
times, to be acid without the presence of the debris of food. 
When the secretion is unusually abundant, as, for instance, 
with children, young persons and, especially, with women during 
pregnancy, caries assumes a more or less acute character. It is 
not' uncommon, remarks Tomes, with persons who have many 
carious teeth, to find the gums swollen, very vascular, and 
covered with a coating of thick, adhesive mucus which may be 
drawn from the gums in long strings. He mentions a case 
where the teeth were rapidly destroyed by caries and, coincident 
with this process, the salivary secretion was scanty in amount ; 
at a later period, the whole of the remaining teeth were almost 
simultaneously attacked near the edge of the gum, producing 
around each tooth an annular belt of softened tissue. He states 
that when there is an abundant flow of saliva and a free secre- 

* Odontological Society of Great Britain Reports, 1865. 
27 



418 ANOMALIES OF THE SECRETIONS. 

tion of mucus, the latter is found clinging to the teeth, instead 
of becoming dissolved in the saliva, and that the mucus must be 
regarded as furnishing the agent by which the dental tissues 
are decomposed. Tomes' conclusion, that the gum when irri- 
tated may furnish an acid secretion, which he regards as justified 
by the fact that caries already existing is promoted by the in- 
sertion of cotton between the teeth, is invalid, as Leber and 
Rottenstein have shown, since these results may be due to the 
fact that the cotton, being a porous substance, necessarily favors 
the processes of decomposition and fermentation which are in 
progress in the vicinity. I have frequently met with tumefaction 
of the gum and papillary hypertrophy in association with dental 
caries in the cadaver; these, to be sure, may, in part, be con- 
secutive affections, still the frequent coincident occurrence of 
an affection of the gum is deserving of notice. 

When there is a diminished secretion of oral fluids and from 
the gum, as is the case in old age, caries assumes a well-marked 
chronic course. In those localities, where only a slight action 
of the secretion of the gum is possible or the latter is removed 
readily by the movements of the tongue, caries is a rare occur- 
rence. When the caries is acute and the crown is destroyed, 
its progress in the roots is a slow process, in consequence of the 
fact that the action of the secretion of the gum becomes less 
direct. While the greatest prominence is^ given to the action of 
the abnormal secretion of the gums, it must not be assumed that 
the influence of the anomalies in the secretions of the salivary 
and mucous glands and of the mucous membrane of the oral 
cavity is underrated, as, indeed, is sufficiently apparent from 
the preceding observations. Injurious effects, however, as a 
general rule, are to be ascribed to the debris of food only in 
cases where the structure of the tooth is defective or there is a 
carious breach of substance. 

It must be acknowledged that our knowledge with regard to 
the quality of the secretions of the oral cavity is imperfect and. 
at all events, it is a question whether the injurious effects are 
due to them alone or rather to the products of their decomposi- 
tion. It is not known whether a larger or smaller amount of an 
acid (perhaps lactic, and with regard to which organic chemistry 



THEORIES OF CARIES. 419 

teaches us that it occurs frequently in partially-decomposed 
animal fluids) shortens or prolongs the process, or if different 
acids modify, in various ways, the course of caries. The 
presence of lactic acid, particularly, is assumed since C. Schmidt, 
of Dorpat, has succeeded in demonstrating the frequent occur- 
rence of this acid in the usually acid juice (Saft) obtained from 
long bones affected with osteomalacia. It also remains to be 
decided whether butyric, valeric, or formic acids, which H. 
Fischer obtained from strongly-alkaline or acid pus, do not 
occur as products of the decomposition of the puriform secretion 
of the gums. 

If the continuity of the enamel membrane is interrupted by 
fissures in the enamel, or has become brittle and friable in conse- 
quence of the presence of leptothrix masses, and acids have access 
to the enamel, then the calcareous salts within the prisms are 
reached quite readily since the organic investments of the latter 
are capable of offering only slight resistance ; indeed, we learn 
by chemical analysis that the organic substances of the enamel 
amount to scarcely more than three per cent. Primarily, the 
action of the acid is confined to narrow limits, and it may be 
assumed upon good grounds that a simple solution of the cal- 
careous salts does not take place, but that the acid enters into 
combination with the latter and the newly-formed salts, destitute 
of an organic cement, readily become disintegrated. If we con- 
sider that the acid spreads in the course of the groups of enamel 
fibres, it will readily be understood that, on the one side, the 
action is confined to definite limits and, on the other, an under- 
mining of the adjacent portions of the enamel ensues. If the 
continuity of the enamel prisms is broken, the normal transpar- 
ency of the enamel, at the corresponding part, is destroyed and 
a white spot makes its appearance. If the action of the acid is 
slow, we find a more abundant deposit of pigment. Possibly, 
decalcification and putrefaction occur in common in this case. 

When a circumscribed breach of substance has been effected 
in the enamel, materials entering from the outside, tenacious 
mucus, leptothrix and particles of food, are more likely to be- 
come impacted in the jagged excavation which then affords a 
more favorable locality for the action of acid ; with this condi- 



420 ANOMALIES OF THE SECRETIONS. 

tion, the acid continues its deleterious action undisturbed by the 
neutralizing property of the salivary fluid, and its effects are 
manifested by a yellowish discoloration of the adjacent portions 
of the dentine, even while the latter is still covered by a thin 
layer of enamel. 

As will be evident, the larger the carious cavity in the enamel 
and the smaller the aperture leading to it, so much the greater 
will be the danger that the dentine will be extensively involved. 
As the dentine contains 28 per cent, of organic matter, the pro- 
cess of decalcification in it takes place quite rapidly leaving be- 
hind the organic residue, the so-called dental cartilage. In con- 
sequence of the action of the acid, death of the affected dentine 
ensues, and its decomposition, in which, as above observed, lep- 
tothrix buccalis is the active agent, takes place from the exterior 
towards the central portions. A carious cavity is formed in the 
dentine, usually larger than that in the enamel ; this affords a 
receptacle for particles of food, which frequently cannot be 
reached except with difficulty, and hence readily becomes the 
seat of acetous fermentation. 

The shape of the carious cavities in the enamel and dentine 
depends partly upon the location in the tooth and partly upon 
the quality of the enamel and dentine. Xear the neck of the 
tooth, the carious excavations are flattened, while those upon 
the masticating surfaces of the molars are always very large in 
comparison with the orifices leading to them. The thicker and 
more compact the enamel, the greater resistance does it offer 
and the more extensive is the destruction of the dentine beneath 
the enamel ; in these cases, therefore, the cavity is always very 
deep, while flattened cavities occur where the enamel is thin and 
has a more lax structure. The greater the extent of the ex- 
posed dentinal surface, the more extensive will be the portions 
affected. 

The cause of the very marked carious pigment deposits in the 
enamel and dentine remains undetermined ; it cannot lie in the 
organic, changed matter alone, since the discoloration is mani- 
fested with equal intensity in both tissues, and between the latter 
there is a marked difference in respect of the percentage of or- 
ganic matter which they contain. When the action of the acid 



THEORIES OF CARIES. 421 

upon the enamel and dentine takes place slowly, the intense, 
carious pigmental degeneration does not extend to a great depth, 
the cartilaginous softening is limited to a narrow zone, and the 
disintegration ensues so gradually that the proliferating lepto- 
thrix buccalis could not possibly penetrate except to a very 
short distance. 

The distinction between caries of bone and of dentine is il- 
lustrated by caries of the cement which is characterized, also, by 
its progress from the exterior towards the central portion of the 
tooth and by a progressive deposit' of pigment, together with a 
peripheral softening. In the premolar of the horse, where the 
vascularized osseous substance forms such thick layers, the pro- 
cess is the same as in the cement of human teeth, with the ex- 
ception that in the former it assumes a well-marked chronic 
character. The death of the osseous substance spreads, gradu- 
ally, from the exterior without any manifestation of an inflam- 
matory reaction. 

Since, then, caries gives evidence of its dependence upon ex- 
ternal causes in all three dental tissues, the question arises, 
what processes occur in connection with the very rare softening 
and melting down of the dentine in the direction from the pulp- 
cavity towards the periphery ? A case has been related (com- 
pare p. 191) where a central softening of the dentine occurred 
without any trace of ordinary caries. Leber and Rottenstein,* 
also, report a case of so-called central caries, where a bluish dis- 
coloration appeared upon three incisors without any trace of 
caries. By means of holes made in two of them, the entire in- 
ternal portions, as far as the enamel, were found to be com- 
pletely softened, decomposed and of a brownish hue ; even the 
roots were deeply excavated. The third tooth was not touched. 
The patient recollected that she had a fall, in her childhood, 
striking upon the teeth, and that this was followed by a swell- 
ing of the face. Leber and Rottenstein express no opinion as 
to the cause of the destruction of the dentine in this case and 
state that such cases ought not to be confounded with ordinary 
dental caries. A. Scheller, of Warsaw, f reported two cases of 

* Op. cit., p. 11. f Deutsche Viertelj. f. Zahnh., 1870. 



422 ANOMALIES OF THE SECRETIONS. 

this description, the second one of which is of especial interest 
and is similar to that of Leber and Rottenstein. He expresses 
an opinion that the central caries of the teeth is to be regarded 
as a process of decomposition which is engendered by the disor- 
ganization (Verjauchung) of the pulp. 

The condition found in gangrene of the pulp (compare p. 183) 
points to the presence of a fatty-acid as a product of decompo- 
sition ; it may be possible, then, that a fatty-acid is formed in 
the necrotic pulp, capable of destroying the dentine. Magitot 
ascertained (compare p. 408 et seq.) that butyric and lactic 
acids are very similar, in respect of the mode and degree of 
their action upon the teeth. At all events, the so-called central 
caries cannot be regarded as a variety of ordinary caries, but, 
obviously, must be classed with the inflammatory affections of 
the pulp. 

'•' In proof of the occurrence of an internal caries, which has 
been classed with caries of bone," says Heider, " the foul, some- 
times exceedingly nauseating odor occasioned by carious teeth 
has been taken into account and referred to a secretion from 
carious dentine. But," he continues, "the peculiar, purulent 
odor never occurs except with a patent pulp-cavity and arises 
from the gangrenous pulp ; while the foul odor of carious teeth, 
when the pulp-cavity is closed, is occasioned by the putrefying 
debris of food, which accumulates in such cavities, and disap- 
pears if the latter are kept clean. The preceding must not be 
confounded with the foul odor occasioned by the accumulation 
of the secretion of the gum between the teeth and, perhaps, by 
coagulated blood, or is communicated by plugs of cotton in the 
cavities." 

The carious process may be checked, but it cannot be cured. 
An acute form may become chronic, and an arrest may ensue ; 
this is a particularly common occurrence, as has been observed 
before, on the carious roots, upon which, however, it is possible, 
always, to discover a carious superficial layer containing deposits 
of pigment. 

Duval* and various other authors have applied the term caries, 

* Magitot, op cit., p. 30. 



THEORIES OF CARIES. 423 

which resembles a "usure" (Usur), to a partial defect which 
occurs upon the neck of the tooth, and has been described as 
wedge-shaped (comp. p. 253). Although Magitot admits that 
these defects present all the appearances of a true usure, still he 
has pronounced them to be instances of healed caries of the 
neck of the tooth or dry caries, without, however, adducing any 
reasons in support of this opinion. The healing process is said 
to be induced partly by the resistance of the pulp and partly 
by the removal of the injurious exciting cause. 

The action of the acid requires a certain length of time, 
whether. the secretions of the gums, the lips, the buccal mucous 
membrane or the debris of food, act as its vehicle, and this 
period is shorter or longer, as the local relations are more or 
less favorable for the reception of the acid vehicle. Hence 
caries makes its first appearance in the pits and grooves or on 
the contiguous and facial surfaces of the teeth. 

The effects of equivalent acid vehicles vary in the different 
kinds of teeth in the same individual and, also, in those of dif- 
ferent persons. The frequency of caries is diminished under 
the following circumstances : a, if the effect of the acid is neu- 
tralized, as is the case upon the lower incisors which are bathed 
in saliva almost constantly, and upon which deposits of tartar 
are very common. The deposition of the latter, probably, pre- 
vents the occurrence of the carious process in the contiguous 
locality, but still chronic caries may be in progress upon one 
surface, while the deposit of tartar takes place upon another ; 
b, if the position of the teeth is corrected so that their contigu- 
ous surfaces correspond with the normal arrangement; c, if the 
teeth receive proper care and they are protected against the 
action of injurious agents; d, if the tooth is constructed in a 
solid manner and its surface presents a normal smoothness; e, 
if all the teeth and the oral mucous membrane, together with 
the glands, are regularly constructed with reference to the modi- 
fications engendered by race and hereditary tendencies. 

The last-mentioned factor is the most important element in 
the determination of the frequency of caries in general and is 
intimately connected with the structure of the entire organism. 



424 ANOMALIES OF THE SECRETIONS. 

The quality of the nutritive material has only a secondary im- 
portance. 

The structure of the individual tooth has an essential influ- 
ence upon the course of caries, and the teeth may be divided 
into groups with reference to their power of resisting the dis- 
ease. Our present methods of investigation are not yet perfect 
enough to enable us to determine with exactness, the individual 
differences in the degrees of hardness of the enamel and dentine, 
the knowledge of which is of importance in determining the 
treatment and prognosis. A. Alphons, of Cracow,* divided the 
teeth into six classes, with reference to the treatment of caries 
by filing and filling. 

Heider communicated to me his views upon this point as fol- 
lows: With regard to the predisposing conditions in the struc- 
ture of teeth which are attacked by caries, it is found that bluish 
or grayish-white teeth, with a slight polish, very frequently are 
attacked simultaneously by acute caries, while, on the other hand, 
yellowish-white teeth, with smooth, polished enamel, usually are 
affected by chronic caries only, and in isolated cases. The first- 
named kind of teeth is furnished with less solid enamel and less 
compact dentine, as is indicated most decidedly by the use of 
the file and excavator. Some teeth can be operated upon with 
great ease, even with inferior files, and leave upon the file a 
large quantity of dentine, reduced to a white, unctuous mass, 
while, on the other hand, the second named kind of teeth offers 
great resistance to the action of the file and is affected only to 
a slight degree, comparatively speaking, even by the best files, 
upon which they leave only a scanty, white, powdered mass of 
dentine. The enamel and dentine, therefore, present two varie- 
ties in quality, the gradations of which determine the varying 
susceptibility of the teeth to caries. 

If it is true, as Gladstone cites from Lasseigne, in his lectures.f 
that the molar teeth contain a greater amount of mineral sub. 
stance than the incisors, and that, with increasing age, the teeth 
present, especially, a large decrease in the amount of carbonate, 



* Deutsche Yierteij. f. Zahnheilk., 18 

f Quarterly Journal of Dental Science. 1S5" 



THEORIES OF CARIES. 425 

as compared with that of phosphate of lime, then we should have 
several datas as to the course of the carious process according 
to the kind of tooth affected and to the age. 

From the foregoing observations, it appears that caries of the 
teeth is a process which has its origin, chiefly, in the abnormal se- 
cretions of the gums and, likewise, in those of the rest of the oral 
mucous membrane and of the salivary glands, and, commencing 
at suitable points upon the exterior of the tooth, spreads in the 
direction of the pulp-cavity. In consequence of the decomposi- 
tion of the secretions, acids are formed which extract the cal- 
careous salts from the hard tissues and give rise to a disinte- 
gration of the affected portions of the latter, in which no inflam- 
matory reaction occurs. The destructive process is promoted, 
essentially, by the accumulations of secretions and particles of 
food, and opportunity is afforded for the proliferation of lepto- 
thrix buccalis, in the dead and softened dentine. The exclusion 
of an acid in the development of well-marked chronic caries 
(caries sicca, carbonacea of writers) is not established upon 
scientific grounds. 



426 NEUROSES. 



VII. NEUROSES. 

Under this head we have to consider the disorders of sensi- 
bility within the territory of the trifacial nerve which, as we 
know, is a mixed nerve, being composed, for the most part, of sen- 
sitive, but, also, containing motor and secretory fibres. The por- 
tion of its territory of particular interest to us includes the 
branches of the second and third divisions, which supply the 
teeth and gums on the corresponding side, but, at the same time, 
it is necessary to keep in view the territory of the other ramifi- 
cations, the points of their origin, together with the numerous 
anastomoses and ganglionic communications throughout the en- 
tire course of the nerves, in order to appreciate fully the com- 
plicated morbid phenomena of nerve-life. 

In consequence of the obscure nature of the subject and our 
present imperfect means of observation, only a few anatomical 
changes in the nerves and ganglions in neuralgias are recognized. 
I had the opportunity of examining a series of nerves which were 
resected by Schuh for the relief of facial neuralgia, and satisfied 
myself that, in the majority of cases, it is possible to demonstrate 
disordered conditions both in the neurilemma and in the nerve- 
tubes. In the former, an hyperaemic swelling occurs, and the in- 
terstitial connective tissue of the nerve-tubes acquires a finely 
granular cloudiness ; in the latter, a finely granular metamor- 
phosis of the medulla is observed. The latter abnormal, refrac- 
tive, protruding contents, however, are found only in separate 
tubes or in a small group of tubes, while the remaining tubes 
contain a perfectly normal medulla. In old chronic cases, pig- 
mented granular spots are found in the neurilemma, and a crum- 
bling disintegration of the greater portion of the medulla is ob- 
served. The grains which fill and protrude from the nerve- 
tube, sometimes, are quite large, glittering, and roundish, at 
others, minute molecules; the axis-cylinders, when removed, 
present similar grains which are adherent and collected to. 



EXCITING CAUSES OF NEURALGIAS. 427 

gether in clusters. In one instance, I found quite large, highly 
refractive, roundish bodies, symmetrically arranged in longitu- 
dinal chains and resting upon separate nerve-tubes. These were 
entirely soluble in hydrochloric acid and, therefore, were calca- 
reous grains. They were also found interspersed in the inter- 
stitial connective tissue. 

These appearances which have been described clearly indi- 
cate that, in most cases, a neuritic process [neuritis] ensues, which 
pursues a more or less active course and, in protracted cases> 
induces an obliteration of the nerve-medulla. 

Rosenthal* also mentions knotty swellings of resected 
branches of the trifacial nerve (consisting of connective tissue 
and interposed nerve-fibres), like the knots which are met with 
in the divided nerves after amputations. 

We know nothing in regard to the affections of the ganglions 
in the course of the trigeminus, in connection with neuralgias; 
in one instance, in a case of prosopalgia, I found an evident 
pathological change in the Gasserian ganglion. f The ganglions 
on both sides presented numerous calcareous grains of various 
forms. The ganglionic cells contained abundant deposits of 
pigment. The ganglion of the affected side presented a quite 
noticeable swelling, and the bloodvessels of the connective tissue, 
which invested it and surrounded the nerve-bundles of the nodu- 
lar enlargement, were very full of blood, so that there could be 
no doubt of a previous exudative process in this ganglion. An 
inflammatory affection at the point of origin of the trifacial 
nerve was observed by Bensow, and Beveridge described a new- 
formation upon the trunk of the fifth nerve. 

These inflammatory processes in the continuity of the trifacial 
nerve are consecutive in most cases, and may have their focus 
of irritation (Reizungsherde) at the periphery of the branches 
of the second and third divisions, the consideration of which is 
involved in our present subject. The following are the exciting 
causes of neuralgias within the precincts under consideration; a, 
chronic inflammation of the pulp, since this and its products 

* Handbuch der Kinderkrankheiten, p. 490. 
■j- Scbub Ueber Gesichtsneuralgien, p. 19. 



428 NEUROSES. 

maintain a constant irritation of the pulp-nerves; 0, new-forma- 
tions of hard dental tissues within the pulp, inasmuch as they 
irritate the remaining nerves of the pulp, under certain circum- 
stances; c, proliferations of cement at the extremities of the 
roots, whereby the nerves which enter the teeth are bent more 
or less from their proper course or the same nerves at a dis- 
tance from the apices of the roots, together with the nerves of 
periosteum of the root, are irritated; d, chronic inflammation of 
the root-membrane, with its sequels, particularly in the vicinity 
of the apex of the root; e, new-formations of the root-mem- 
brane when they encroach upon the precincts of the nerve- 
branches; /, periostitis, especially in the grooves or the foramina 
which serve for the transit of the dental nerves'; </, osteophytes, 
which occasion an irritation of the periosteal nerves; h, tume- 
faction of the mucous membrane and periosteum of the antrum 
of Highmore give rise to pain and even a neuralgia of the pos- 
terior, superior dental nerves (Schuh) in otherwise sound teeth, 
which circumstance Luschka explains by the fact that the dental 
nerves pass through complete bony canals in some places, but in 
others lie in very shallow grooves in the bone, so that they are in 
immediate contact with the tissue of the periosteum, and, if the 
latter be removed, they become exposed; i. anomalies of position, 
whereby resorption of one or another root or of the crown of the 
adjacent tooth, is occasioned by the growth of the roots of the 
displaced tooth, and the contiguous portion of the root of the 
former is subjected to a continual irritation ; Jc, teeth which re- 
main imbedded within the jaw sometimes irritate the dental 
nerves of other teeth by the growth of their roots ; /, inflamma- 
tory irritation of the gingival nerves which cover the coronal por- 
tions of teeth during the first dentition; m, inflammatory irrita- 
tion of the gingival nerves in connection with the difficult erup- 
tion of teeth during the second dentition, especially of the wis- 
dom teeth ; n, tumors of the jaws, inasmuch as they sometimes 
occasion an irritation of the dental nerves ; 0, foreign bodies 
which have penetrated into the pulp ; p, lesions produced by 
unsuccessful extractions of teeth. 

When such peripheral foci of irritation exist, as the resected 
nerves in facial neuralgia show, the trunks, from which the 



IRRADIATION OF THE PAINS IN NEURALGIAS. 429 

dental nerves are given off, become inflamed, their sheaths are 
found in an hyperaemic condition, and hence the possibility is 
afforded for communicating nerves, which are contained in a 
common fibrous envelope, to become involved. Moreover, it is 
readily explicable that hyperesthesia is induced by inflammatory 
swellings in localities where the radiation of the divisions of the 
trifacial nerve is confined to a contracted space. Hyrtl* calls 
attention to the fact, that the branches of this sensitive cranial 
nerve traverse tightly-inclosed,. long canals in the bones, as the 
infraorbital, alveolar, zygomatic branches, &c, and, therefore, 
on the occurrence of nutritive disturbances of their sheaths 
from rheumatism or congestion, with thickening and tumefac- 
tion, they are subjected, necessarily, to pressure which is mani- 
fested by sensations of pain. 

Rosenthalf states that periostitis, involving portions of the 
bones through which the passage of the trifacial nerve takes 
place, is a frequent exciting cause, and says neuralgia of this 
nerve is due, most frequently, to exposure to cold. Without 
detracting from the influence of the latter, I am convinced, 
nevertheless, that in most cases there is a primary neuritic con- 
dition [neuritis] of a peripheral branch of the trifacial nerve, 
and that the exposure to cold simply furnishes a cause for the 
farther extension of the previous inflammatory condition in the 
course of the branches of the nerve. 

Peripheral irritations of the trifacial nerve, as we know, fre- 
quently arise at the point of exit of the nerve from the cranial 
cavity, in consequence of inflammatory affections or tumors at 
the base of the brain, and a thorough examination is required 
in order to determine whether the focus of irritation is centric 
or peripheric. In this case, it is supposed, of course, that the 
patient refers the pain to the periphery and not to the irritated 
portion of the nerve. 

Another and frequent source of error, in the determination of 
the focus of irritation, arises from the irradiation of the pains, 
by which is meant that they extend far beyond the limits of the 



* Topograph. Anatomie, 5 Aufl., I, p. 345. 
f Op. cit.,p. 193. 



430 NEUROSES. 

seat of irritation and, sometimes, are more severe than the pain 
felt at the original focus of irritation. In these facts, we have 
an explanation of the inexact and varying statements of patients 
with regard to the locality of the pain, whereby the surgeon is 
not a little perplexed in deciding upon the resection of one or 
another nerve. 

Further proof of the difficulty attending the localization of 
the focus of irritation is furnished by the fact that resection of 
painful branches of the trifacial nerve, in most cases, affords only 
temporary relief from pain, which rarely continues longer than 
a year. Resection of a sensitive nerve really effects nothing 
but an interruption of its conductivity and, as soon as the latter 
is restored by the regeneration of the nerve, the pain is renewed 
and becomes as violent as it was previous to the operation : 
hence it is proved that the focus of irritation was not detected 
and that it must have been located somewhere else than in the 
resected portion ; the irritation persisted after the resection, but 
consciousness of it was lost since its connection with the brain 
was cut off. 

Another important question arises : Is there any point to 
which the pain is referred constantly ? Schuh,* after very ex- 
tensive observations, came to the conclusion that the fixed pain 
is wanting very frequently, although Valleix maintains the op- 
posite view. It is described by the patients, he says, as dull, 
heavy, gnawing, dragging and somewhat burning, and is not 
perceived throughout the entire course of the nerve or branch, 
but is limited to a circumscribed locality. Usually, it is not very 
severe and, sometimes, it continues, with varying intensity, for 
hours or days together. I am disposed to agree with Schuh, 
since it is a physiological fact that the sensibility of nerve-fibres 
may become blunted, at least for some time, if they are sub- 
jected to severe or continued irritation. If, however, we find 
no continually painful locality, it becomes a more difficult matter 
to ascertain the locality of the focus of irritation. 

If the clinical phenomena indicate such a fixed point, they 
may be divided into those which are confined to the focus of 

" :; " Ueber Gesiebtsneuralgien, 1858. p. 3. 



REFLEX PHENOMENA. 431 

irritation, local or primary, and into periodical or secondary. 
The most prominent symptom is the disorder of sensibility, 
which we term pain. Besides the sensitive fibres of the trifacial 
nerve, its motor and secretory fibres and even those of other 
nerves are attacked by reflex action through the small reflex 
centres, the ganglions, or through the central nervous system. 
Fibres of the sympathetic, also, become involved in the irritation. 

With regard to the localities from which the pain radiates in 
the paroxysms, Schuh observes, they originate either at the 
points where the sensitive branches of the fifth pair emerge from 
the canals or grooves of the bone and enter the soft parts of the 
face, in the peripheral, terminal ramifications in the skin, mucous 
membrane, or teeth, or, finally, where the terminations of the 
two divisions of the nerve join or communicate with one another. 
Among the painful points determined by Schuh and Valleix, 
the following may be mentioned, in the present connection : 
a, the point of exit of the infraorbital nerve from the infraorbital 
canal ; 5, the gum of the upper jaw in which the anterior, mid- 
dle or posterior dental nerves are the seat of the affection ; 
c, the condyle of the jaw, when the pain appears to be located 
in the inferior dental nerve, in most cases, and particularly at 
the point of its entrance into the dental canal ; d, the point of 
exit of the mental nerve on the chin. 

The reflex phenomena have reference both to the motory and 
secretory fibres. The motor symptoms are manifested, chiefly, 
in the facial muscles, by clonic or tonic contractions. According 
to the statements of Schuh, with intensely painful neuralgias, 
especially when the cause is seated within the cranial cavity, it 
also happens that, not only the muscles of the face and eyes, but 
nearly all the muscles of the body are thrown into a state of 
tonic contraction, so that the patients appear rigid and immov- 
able, like a statue, and retain, perfectly, the position in which 
they were at the moment of the attack. The rigidity of the 
muscles continues until the paroxysm of pain ceases. Very 
rare cases have been observed where the sensibility of certain 
points was so acute that the sudden and unexpected contact of 
anything would even cause the patient to fall, with loss of con- 
sciousness and convulsions. 



432 NEUROSES. 

The affection of the secretory apparatus is manifested upon 
the^ surface of the skin, by perspiration in the region of the 
face, and an increased secretion, subsequent to the paroxysm, 
from the mucous membrane and corresponding glands, as the 
mucous, salivary, and lachrymal glands. 

Irritation of the fibres of the sympathetic is effected through 
the ganglions within the territory of the trifacial nerve, namely, 
in the eye through the ciliary ganglion, in the ear through the 
spheno-palatine and otic ganglions, in the secretory apparatus 
on the floor of the oral cavity, through the submaxillary 
ganglion.* 

It is necessary to refer in this connection to a special exciting 
cause of facial neuralgia, which, in my opinion, is of great im- 
portance, namely, the extraction of teeth. Schuh observes that 
it is particularly noticeable, that very many patients date the 
origin of their suffering from the time of the extraction of one 
or several decayed teeth. Although he suggests caution in ac- 
cepting this statement, he is convinced, nevertheless, from ex- 
tensive observations upon the subject, that the extraction of un- 
sound teeth, especially if the operation is performed with vio- 
lence or is repeated at one sitting, sometimes is the cause of 
neuralgias, in consequence of the stretching and laceration of 
the delicate nervous filaments. Many well-informed persons, 
who were accustomed to observe, carefully, their sensations and 
conditions of body and have stated confidently and positively 
that they were able to distinguish a difference between the tooth- 
ache which they felt before, from the slight and soon increasing 

* Through irritation of the sympathetic nerve the uterus is brought into 
close relation with the teeth. It is a well-known fact that puins of the teeth 
often occur during pregnancy as well as during certain inflammatory affec- 
tions of the uterus, and cases have been recorded of recovery from pains and 
symptoms of disease in the uterus upon the extraction of one or more teeth. 
In a large number of cases of diseases of the uterus, the teeth are seriously 
affected by caries. Out of more than twenty-five patients suffering from 
uterine disease, in a hospital for diseases of women in this city, examination 
of their mouths showed extensive caries of the teeth in all but one. This is 
a subject which needs thorough investigation. At the present time, our 
knowledge is so limited that we cannot say with much assurance how much 
the teeth and the uterus affect each other in the reciprocal action of condi- 
tions of disease. — T. B. H. 



FACIAL NEURALGIA CAUSED BY EXTRACTION. 433 

neuralgia which occurred a few hours after the extraction of the 
tooth, would admit no other exciting cause than the one in 
question. 

If we consider the fact that, in connection with caries of the 
teeth, the pulp becomes inflamed and entire bundles of nerves 
manifest evidences of degeneration, while, in the neuritic pro- 
cess, which occurs in neuralgia, single nerve-tubes only are 
affected in the manner already described, there are grounds, in 
my opinion, for the assertion that the two processes present 
anatomical differences, and that the darting pains in facial neu- 
ralgia are due to the affection of the separate nerve-tubes. 

If we consider, also, that, after amputation of the limbs, sensi- 
tive nerve-tubes sometimes grow in large numbers from the sur- 
faces of the transversely-divided nerves, as I proved* in the 
year 1855, it is probable, that an analogous process occurs in 
nerves which have been lacerated in the extraction of teeth ; 
indeed we have an intimation of such an occurrence in the pains 
in the sockets from which teeth have been extracted. If, now, 
a predisposition (Diathese) to the development of new-formations 
of nerves of this description exists in an individual, or if, in con- 
sequence of unskilful extraction, the nervous branches which 
supply the teeth are not separated from their attachments to 
the main stems, but are badly bruised and crushed, and the 
main stem itself is injured more or less, the condition of irrita- 
tion which is produced in the nerves may, sometimes, induce a 
proliferation of the sensitive fibres. Actual proof of this sup- 
position remains to be established in the future. With regard 
to the diathesis, we may call to mind that such a condition has 
been established for the new-formations of dentine, cement, 
periosteum of the root and gum, and we may, upon good 
grounds, speak of a progressive new-formation, i. e., of one 
which extends to the adjacent tooth. It is quite reasonable, 
therefore, to assume a diathesis for the proliferation of nerves 
after their laceration. Premising this, it is quite easy to un- 
derstand that the extraction of teeth for the relief of facial neu- 
ralgias only aggravates the evil. 

* Zeitschr. d. Gesellscli. d. Aerzte zu Wien. 
28 



434 NEUROSES. 

From this point of view, I regard the suggestion of Dobbelin* 
as .a fortunate one, namely, to substitute another operative treat- 
ment in place of the resection, which necessitates deep incisions 
and, indeed, affords relief for a few months only, when the focus 
of irritation is located in the nerves of single teeth. He cites a 
series of cases which occurred in his practice, where he produced 
a complete cure of facial neuralgia, particularly of the infra- 
orbital nerve, by exposing the pulp-cavity with a trephine and 
killing the nerves of the root in all non-carious bicuspids and 
molars, and by killing the nerves of the coronal and radical 
pulp in cases in which perforating caries had occurred. One 
case is particularly instructive, where the infraorbital nerve 
together with a portion of the upper jaw around the infraorbital 
foramen had been removed, but without a successful result ; he 
trephined all the bicuspids and molars which remained in the 
jaw, and effected a cure. 

With the multiplicity of the above-mentioned foci of irritation 
of the dental nerves (comp. p. 427) and the indefiniteness of 
the painful sensations, it frequently happens that nothing is left 
in the way of treatment, but to destroy, experimentally, the 
supposed focus of irritation in an affected tooth or in a root. The 
result, then, will confirm or disprove the correctness of the sup- 
position. It is self-evident that, in an isolated case in which the 
experiment is attended with a successful result, we must be on 
our guard and avoid the false conclusion, post 7toc, ergo propter 
hoc. If, however, in a series of observations we find that the 
same favorable effect ensued in equivalent cases, or a complete 
and permanent cessation of the symptoms followed the removal 
of the centre of irritation in individual cases, or a notable abate- 
ment was observable, then in one case the supposition is raised 
to a certainty, and in the other it is reduced to a mere proba- 
bility, or the latter, even, may be questionable. 

When the nerves of the gum are subjected to a severe irrita- 
tion by the advancing crowns during the first dentition, pain of 
a radiating character is developed in the sensitive organism of 
the child, reflex phenomena occur in the form of convulsions or 

* Deutsche Viertelj. f. Z.. 186& 



ABSTRACT OF CASES. 435 

epileptiform paroxysms ; in a series of well observed cases, these 
symptoms disappeared immediately after the division of the irri- 
tated nerves of the gum with the lancet. Hence, in these cases, 
the centre of irritation without doubt was located within the 
gum. Upon pure theoretical grounds, also, the above-men- 
tioned consecutive irritations of the central nervous system must 
have their origin in the irritated nerves of the gum. 

The recorded observations of many observers, also, show that 
anomalies in the second dentition, in children of a nervous tem- 
perament, sometimes occasion neuralgias, convulsions and epilep- 
tiform paroxysms, and, therefore, it is evident that, in such cases, 
the physician should not neglect to examine the condition of the 
teeth. An unusually difficult eruption of the wisdom teeth may 
be the cause of similar symptoms and even of mental aberra- 
tion. 

The following series of cases, which I have endeavored to make 
quite extensive in consequence of the great importance of the 
subject, will serve to illustrate the preceding observations with 
reference to the focus of irritation, when it is situated in the 
dental nerves. 

Breithaupt* reported a case of prosopalgia caused by an im- 
pacted canine in the upper jaw. The affection was removed by 
the extraction of the tooth. Forgetf observed a case of neu- 
ralgia which was occasioned by a wisdom tooth in the axis of 
the jaw. HesseJ met with a case of neuralgic pains in the lower 
jaw, induced by a wisdom tooth which was imbedded within the 
jaw in an oblique position, with Us crown directed towards the 
molar in front of it. The molar was removed, the pain ceased 
and the patient soon recovered. F. H. Thomson§ observed a 
case of facial neuralgia resulting from the concrescence of the 
roots of the wisdom and second molar tooth, which prevented 
the descent of the former. Esquirol reports the case of a woman 
who recovered from insanity after a crucial incision was made 
in the gum in order to promote the eruption of the wisdom 
tooth. Ashburner relates the case of a young man, seventeen 



* Deutsche Viertelj. f. Zahnh., 1861. f Des Anomalies dentaires, 1859. 
% Gazette des Hopitaux, 1856. \ Dental Review, 1860. 



436 NEUROSES. 

years of age, who was afflicted with delirium, destructive mania 
and delusions. Incisions were made in the gum covering the 
wisdom teeth, and recovery ensued in a week. Forget cites a 
case of severe dental neuralgia, caused by a wisdom tooth, the 
crown of which was inclined anteriorly and exerted a strong 
pressure upon the second molar. The affection led the patient 
to commit suicide. He jumped from the upper story of a house, 
tetanus succeeded and, finally, death. Hancock observed a re- 
covery from trismus and pain under the right ear, after the ex- 
traction of the first molar. Dobbelin cites a case where tetanus 
occurred simultaneously with the extraction of a tooth. Ben- 
sow* had under his treatment a young man suffering from very 
severe neuralgia in the upper first molar which, evidently, was 
free from any disease. Extraction proved to be useless, and 
the patient died on the fourth day after the operation. Exami- 
nation after death showed nothing worthy of observation in the 
mouth : the brain was healthy ; at the origin of the fifth nerve, 
a collection of pus, the size of a mustard-seed, was found. I am 
inclined to question whether this was not the result of the un- 
avoidable injury to the nerves of this tooth in extraction, which 
were in a condition of hyperesthesia. f 



* British Journal of Dental Science, 1867. 

f J. Tomes (System of Dental Surgery) states that two cases came under 
his notice in which epilepsy was consequent upon diseased teeth, the most 
prominent feature being exostosis of the roots. " A lad, a farm laborer, from 
Windsor, was admitted into the hospital for epilepsy. The usual remedies 
were tried for six weeks without effect. His mouth was then examined, and 
the molar teeth of the lower jaw were found to be much decayed, and of 
some of these the fangs only remained. He did not complain of pain in the 
diseased teeth or in the jaw. The decayed teeth were, however, removed, and 
the fangs of each were found to be enlarged and bulbous from exostosis. 
During the eighteen months that succeeded the removal of the diseased 
teeth, he had not suffered from a single fit, though for many weeks previous 
to the operation he had two or three per day. This is a case of singular in- 
terest, inasmuch as there was no complication of maladies, and hence there 
could be no doubt as to the cause of the disease, seeing that it immediately 
subsided when the teeth were removed : and it is further useful in showing 
that a sufiicient source of local irritation to induce functional derangement 
may exist without pain being felt in the part where the irritation is applied.*" 

"A similar but less marked case occurred shortly afterwards, in the person 



ABSTRACT OF CASES. 437 

Fox* relates the following case: "The patient was a young 
lady, twenty years of age ; for more than a year she had suf- 
fered from deepseated pain in the face, and in the teeth and 
gums. The pain gradually extended to all the teeth, and one 
by one all those of the lower jaw, with the exception of the 
four incisors, were removed. During this time every kind of 
medical treatment had been resorted to, but without affording 
her any alleviation to her sufferings. At the time the patient 
consulted Mr. Fox, she was only able to take fluid nutriment, 
for the teeth of the upper jaw were so tender that the slightest 
touch caused extreme pain. There was a constant flow of saliva 
from the mouth, and the palpebrse of one eye had been closed 
for nearly two months [and when opened the sight of the eye was 
affected]. The most painful tooth was extracted. This was 
the first molar of the upper jaw, situated under the eye, the 
palpebrae of which had become closed. The fangs of the tooth 
were much enlarged ; its removal was attended with great bene- 
fit, and two days after, the affected eye could be opened. This 
only afforded partial relief, and eventually all the teeth were 
removed, when the patient was at length relieved from her suf- 
ferings." This case, probably, was one of a progressive prolif- 
eration of cement, where the process advances from one tooth 
to another, and, in my opinion, it would have been a suitable 
case for the method of treatment recommended by Dobbelin 
(comp. p. 434). Thomsonf describes a case of prosopalgia re- 
sulting from exostoses of the roots of the wisdom teeth. 

of a policeman. He had fits, which were greatly relieved by the removal of 
an inferior wisdom tooth, the subject of caries and of exostosis." 

With reference to the first case, an essential point in the argument for the 
stated source of local irritation is wanting, in my opinion, namely, that it 
was possible to bring on the fits by irritation of the decayed teeth. It is, 
also, to be borne in mind that, as Eosenthal observes (1. c, p. 311), particular 
caution is enjoined, both in respect of the prognosis and the estimation of 
the results of treatment, by the frequency of recurrences, even after a remis- 
sion of the paroxysms for several years. Again, no little importance is to be 
attached to the fact that the regulation of the diet, which obtains in the hos- 
pital, exercised a beneficial influence in diminishing the frequency of the fits 
with the two epileptics. 

* Vide Hulme's Lectures, Dental Keview, 1862. 

f Glasgow Med. Journal, 1867. 



438 NEUROSES. 

Hilton* reports the case of a man whose hair, upon the left 
temporal region, became gray, as a result of a carious affection 
of a lower molar. He suffered from neuralgia in the left side 
of the face, for the relief of which he was treated in various 
ways without success. He wore a wig, as the rest of his hair 
was black. The carious, lower second molar was extracted and 
the neuralgia disappeared almost entirely. It is not stated 
whether the hair upon the temple became black again, since the 
patient was not seen again. 

Von Stellwagf regards it as probable that irritations in remote 
portions of the trigeminus nerve may be transmitted through 
the ciliary system to the nervous apparatus which serves for the 
reception of luminous impressions, occasion an' increased excita- 
tion in this and, by producing hyperemia and inflammation, 
give rise to amaurosis (amaurosis trifacialis of Beer). " It is a 
well-known fact," he says, "that it is, by no means, an uncom- 
mon occurrence for intense irritations of one or another division 
of the trifacial nerve to lead to hypercesthesia, and later to 
hyperemia and inflammation in the territory of the ciliary 
nerves." " Hyperesthesia of the ciliary nerves^ may also be in- 
duced by exfoliation of an alveolar process, abscesses in the 
roots of a tooth, and the impaction of foreign bodies in an 
alveolus." He cites the following cases in his notes. Galen- 
zowski cured a complete amaurosis which occurred in conjunc- 
tion with a most violent, intermittent neuralgia in the temporal 
region, face and, especially, in the eye, by the extraction of a cari- 
ous bicuspid upon the root of which there was a splinter of wood 
that had produced an irritation of the dental nerves. (I once 
found a splinter of wood which entirely filled the root-canal of 
a carious tooth and, evidently, was a fragment of a tooth-pick. i 
Teirlink relates a case where an impacted fragment of a tooth 
in the upper jaw of a woman occasioned frequent attacks of 
odontalgia, which were accompanied, at different times, by in- 
tense pain in the eyes, intolerance of light, a profuse secretion 



* Lancet, 1861. 

f Ophthalmologie vom naturwiss. Standpunkt. ii. p. t>31 

J Ibid., p. 321." 



ABSTRACT OF CASES. • 439 

of tears, dimness of vision, contraction and immobility of the 
pupil. All treatment was unsuccessful until the fragment was 
removed, when the pain ceased immediately. Hay observed a 
case where a man, who had overworked himself at a fire, suffered 
from an excessive intolerance of light which continued even in a 
dark room. The uncomfortable sensation seemed to start from 
one of the upper incisors. Tapping upon this tooth with a key 
produced most violent, twinging pains. Upon the extraction of 
this tooth, an abscess was found in the root. Recovery ensued 
after the removal of the tooth, and six years afterwards there 
had been no recurrence of the affection.* 

Hutchinsonf observes that far too little attention is given to 
the condition of the teeth as the possible cause of functional or 
nutritive derangements in the globe of the eye or in the cerebral 
centres of vision, and remarks especially upon the importance 
of taking advantage of every opportunity to clear up the subject 
of the possibility of the evil effects of stumps of teeth which are 
left in the jaws. 

In confirmation of this opinion, I will cite the following cases. 
Dr. EmmeuchJ suffered for fourteen years from notable conges- 
tions in the region of one eye, profuse secretion of tears and in- 
tolerance of light. These symptoms were increased by slight 
errors of diet. He found a carious tooth upon the side corres- 
ponding with the affected eye. Almost immediately after the 
extraction of this tooth, the symptoms referable to the eye be- 
gan to abate and, in a short time, they disappeared entirely. 
Teirlink mentions two cases. A first upper bicuspid was ex- 
tracted from the jaw of a young man, for the relief of very 
severe toothache; the patient stated that he suffered from quite 
severe pains in the eye upon the same side, and, on another 
day, he came with a complaint that his sight was affected. The 
pupil was very much dilated. Extract of opium and opium 
ointment were inserted in the alveolus and effected a contraction 
of the pupil and restoration of sight. A woman complained of 

* Comp. also von Stellwag's Lehrbuch der Augenheilkunde, 4 Aufl., p. 
854. 

f Ophthalmic Review, 1866. % Dublin Medical Free Press. 



440 NEUROSES. 

defective vision and excessive secretion of tears. After the 
extraction of a carious root, the sight was restored gradually 
and the excessive lachrymal secretion ceased. Hancock* re- 
ported three cases. A lad, eleven years of age, on waking 
from sleep one month previously, found that he was entirely 
blind. Previously he had nothing the matter with his eyes, and 
when he went to bed on the preceding night he could see dis- 
tinctly. Treatment had availed nothing. The pupils were 
dilated, the iris was motionless and did not respond to the ex- 
citation of light. He was unable to distinguish light from 
darkness. Upon examination of the teeth, Hancock found 
them tightly wedged and crowded together. . Two permanent 
bicuspids and four milk molars were extracted; the same even- 
ing, the boy could distinguish light from darkness, and in the 
following morning he was able to make out objects. From this 
time the boy's sight improved, and eleven days after the opera- 
tion, he was discharged well. A man came to the Westminster 
Ophthalmic Hospital on account of amaurosis of the right eye, 
which had existed for eight months and came on suddenly. He 
could distinguish between light and darkness ; the pupil was 
dilated and fixed. Medical treatment did no good. The second 
upper molar on the right side was found to be diseased, and it 
was extracted. Two days afterwards, he was able to distinguish 
objects, although imperfectly. A few days later, he returned 
home, cured. A patient, twenty-two years of age, had been 
affected with strabismus for three years. A ptosis had existed 
about a fortnight. The left eye was closed. The affection 
came on suddenly, without pain, either in the head or eye. 
After treatment had been employed without success for nine 
days, two carious teeth were found in the left side of the upper 
jaw, which were not painful. The affection had assumed an in- 
termittent character. In the morning, the eye was open : 
towards noon, the lid dropped down and, at evening, it resumed 
its original position. In four days after the administration of 
quinine, the ptosis was cured, the strabismus was improved, so 
that, in fact, no operation was done. Kemptont observed a 

* Lancet, 1859. f Dental Review, 1861. 



ABSTRACT OF CASES. 441 

case, where a woman had suffered for a fortnight from severe 
pains in the right temporal region, which extended over the 
nape of the neck, sometimes affected the side of the face, and 
were accompanied by shooting pains in the globe of the eve. 
Cold applications within the mouth and externally alleviated 
her suffering. There was no toothache. The lower right wis- 
dom tooth was extensively carious, and the gum was swollen. 
During the extraction, she experienced a severe pain across the 
right side of the head, which lasted a few seconds, but no pain 
in the locality from which the tooth was removed. The neuralgia 
disappeared. 

De Witt,* in a man who stated that he had been nearly blind 
in the right eye for twelve years, so that he could merely dis- 
tinguish light from darkness, found a cavity filled with white 
metal in the first bicuspid, and a fistulous opening in its alveolus. 
Upon the removal of the filling, a foul-smelling, sanious matter 
escaped from the cavity of the tooth. Three weeks later, when 
the right eye had recovered so that it performed its functions 
nearly as well as the other, the sensitiveness of the gum re- 
turned and, at the same time, the vision again became affected. 
The tooth was then extracted, and the amaurosis disappeared 
immediately (?). Six days afterwards, the patient was able to 
see with the right eye as well as with the left, except that small 
objects were not clearly recognizable. De Witt remarks that 
the amaurosis had its origin in an irritation of the fifth nerve. 

Cases, also, are recorded which indicate the effect of diseased 
teeth upon the hearing. Certain sounds, such as a creaking 
noise, produce sensations in the teeth. Carious teeth sometimes 
occasion paroxysmal pains in the ear. The following case came 
under the observation of Harvey. A man, twenty-two years of 
age, suffered for three years from attacks of neuralgia in the 
ear, which, occasionally, were accompanied by a foul-smelling 
discharge from the external meatus and lasted several hours. 
The most intense pain was felt in the direction of a carious 
wisdom tooth. This was extracted and the neuralgia was 
cured. Vautierf reported a case of facial neuralgia and deaf- 

* American Journal of Medical Sciences, 1868. 
f G-azette des Hopitaux, 1860. 



442 NEUROSES. 

ness, which was cured by the extraction of an upper wisdom 
tooth. 

James Salter, in his instructive article upon nervous affections 
induced by diseases of the permanent teeth,* expresses the 
opinion that, next to the branches of the trigeminus, the cervical 
and brachial plexuses are most frequently affected by an irrita- 
tion of the teeth. He cites a series of instructive cases. 

Thomas Bellf reported two cases in point. In one, the patient 
had suffered for a year from irregular paroxysms of pain which 
was felt, at first, in the ear and, afterwards, extended across the 
neck and shoulder and along the arm, producing impairment of 
motion in the hand and fingers. Bell ascertained that, two 
years previous to that time, the lower second molar had been 
broken off, in an attempt to extract it, and the roots were still 
in the jaw ; the anterior one had emerged, partially, from the 
socket and lay upon the gum, in an oblique position ; the pos- 
terior root was still firmly imbedded and, evidently, occasioned 
considerable irritation in the surrounding parts ; pressure upon 
this root increased the pain which, in a measure, assumed the 
character of the paroxysmal pains from which the patient had 
suffered so long. The stumps were removed and the paroxy 
did not return. In a second case, there was slight impairment 
of motion in the right arm, with occasional pain and the peculiar 
sensation of formication which is felt when pressure is exerted 
upon a nerve. Finally, the patient noticed that a paroxysm 
was accompanied by an acute pain in the lower second molar 
upon the same side. This fact led to a careful observation of 
the succeeding attack. Bell became satisfied that the contact 
of a sharp instrument with this tooth occasioned a return of the 
sensation in the arm. The tooth was extracted and a complete 
cure ensued, although not immediately. 

F. H. Thomson* mentions three cases of facial neuralgia, 
consequent upon caries of the wall of the antrum. 

These cases are sufficient to show that facial neuralgias and 



* Guy's Hospital Reports, xiii, 1SGS. 

f Anat. Phys. and Path, of the Teeth. 2d ed. 



ANESTHESIA OF THE DENTAL NERVES. 443 

various affections of the eye, ear, the cervical and brachial 
plexuses not infrequently have their origin in an irritation in 
the teeth, and that dentists, and surgeons, especially, should not 
neglect to make a careful examination of the teeth in connection 
with these affections; the experience and knowledge of an edu- 
cated dentist, of course, is requisite for this purpose ; the mere 
extraction of a tooth at random is of no avail. 

Ancesthesia of separate teeth occurs in connection with 
atrophy of the dental nerves, consequent upon previous inflam- 
mations, new-formations, within the pulp or outside of the 
same, following chronic inflammation of the root-membrane, ab- 
scesses at the extremities of roots, &c. Anaesthesia of one or 
another side of a set of teeth has its origin in the trunks of the 
dental nerves or in more central localities. The possibility of 
the existence of new-formations ought to be taken into account 
as a cause of this affection. When apoplexy, tabes, hysteria, 
tumors of the pons Varolii and the posterior lobes of the cere- 
brum, which encroach upon the territory of the trigeminus 
(second and third divisions), give rise to anaesthesia of parts cor- 
responding to the anatomical distribution of the nerves, as shown 
by Ch. Voigt, then the teeth and the gums,* also, become de- 
prived of their sensibility. Rosenthalf cites a case, which came 
under his observation, where, in connection with anaesthesia of 
the second division of the trigeminus on the right side, the upper 
teeth and gums were entirely insensible, while the lower teeth 
and the floor of the oral cavity manifested the normal sensibility. 
At the autopsy, a new-formation, as large as a nut, was found in 
the left half of the pons Varolii. 

* Kosenthal, op. cit., p. 500. f Ibid., p. 77. 



ALPHABETICAL INDEX. 









PAGE 


Abscesses in the alveoli, 






216 


coronal dentine of human teeth, . 






187 


dentine of animals' teeth, . 






187 


gums, 






198 


jaws, 






225 


maxillary periosteum, . 






222 


P«!p, 




. 177, 179 


, 186 


root-membrane, .... 






210 


root, the cause of affections of the ci! 


iary 


nerves, 


438 


tusks of elephants, new-formation of 


osseous substance 




with, 






304 


Absorbent organ, ....... 






79 


Adenomata, ........ 






321 


Adhesion of all the teeth impossible, 






154 


the pulp to the dentine, 






241 


Alveolar abscess, ....... 






216 


arteries, injection of the, 






60 


process, affection of the ciliary nerves caus 


3d by 


exfoliations 




of the, 






438 


arch of the, .... 






23 


enostosis of the, . 






331 


epulis of the, .... 




. 322 


347 


exostosis of the, 




. 228 


327 


hypertrophy of the, . 






228 


interstitial development of bone in 


exos 


toses of the, 


329 


necrosis of the, .... 




. 222 


226 


new-formations of the, 






322 


of the lower jaw, 






25 


of the upper jaw, 






22 


osteomata of the, 




. 228 


327 


purulent infiltration into the, . 






217 


results of fractures of the, . 






223 


senile resorption of the, 






266 


Alveoli, abscesses in the, 






216 


cicatrization of the, 






258 


description of the, 




22, 25 



446 



ALPHABETICAL INDEX. 



PAGE 

223. 263 

. 70 

71 



. 213 
. 2-59 
. 255 

. 23 
439, 441 



438 
440 
438 
443 
426 



on of the 



Alveoli, fracture of the, . 

growth of the coronal, ....... 

partial resorption of the, previous to the eruption of the teeth 
resorption of the, in connection with inflammation of the root 
membrane, ...... 

resorption of the, after extraction of teeth, 
senile, ....... 

septa of the, ...... 

Amaurosis consequent upon dental caries, 

the impaction of foreign bodies in the teeth 

and jaws, 
the malposition of teeth 
trifacialis, ...... 

Anaesthesia of the teeth, 

Anatomical changes in the nerves and ganglions in neuralgias 
Aneurism of the superior palatine artery, to be distinguished from an 

abscess, 218 

Angiomata of the gums, 

Angle of the lower jaw. peripheral and pericellular resorpt 

senile changes in the, 
Anomalies of the secretions, ...... 

Antimony, effects upon the root-membrane, from the use of 
Antrum of Highmore, ....... 

catarrhal inflammation of the, 

cysts of the, 

dropsy of the, ....... 

empyema of the, ...... 

entozoa in the, ....... 

facial neuralgia, caused by caries of the wall of the 
fistula of the, ....... 

foreign bodies in the, 

inflammation of the membranes of the, a sequel of 

root-membrane, 

polypi of the mucous membrane of the, . 
Appearances presented by carious cement, . 

dentine, . 
enamel, 
Arsenic, effects of, upon the root-membrane, 
Articular eminence of the temporal bone, senile flattenin 
Articulation of the lower jaw . 
Artificial caries, 

teeth, caries of, 
Atony of the gums, 
Atrophies, .... 
Atrophy, eccentric, of Kokitansky 
net-like, of the pulp, 
of the maxilla 3 , 

maxillary periosteum, 



319 
269 
. 269 
. 354 
. 215 
. 24 
. 229 
. 351 
22 - 
. 229 



. 442 

219, 352 

. 230 



that of the 



of the. 



4,3 



. 391 

. 384 

- 

O I o 

. 215 

. 270 

. 26 

375, 407 

406, 414 

232 
2-37 



ALPHABETICAL INDEX. 



447 



Atrophy of the pulp, 

resulting from inflam 
root-membrane, . 
socket, .... 
primary or senile, . 
secondary or consecutive, 
senile, of the gums, 
Axial torsions of the crowns, 



nation, 



PAGE 

232 
191 
255 
258 
232 
232 
254 
132 



Bacteria, 195, 211, 358, 407 

Bicuspids, description of the, . ... . . . . . .34 

Blending of adjacent teeth, 

distinguished from twin-formation, 
milk teeth, ........ 

Bloodvessels of the pulp in inflammation, changes in the, . 
Bone, caries of, distinguished from that of teeth, . 
interstitial development of, .... 

growth of, in the jaws, 
resorption of, in the jaws, . 
Brachial plexus of nerves, affections of the, consequent upon 
of the dental nerves, ...... 

Buccal fistula, ........ 

Biihlmann's fibres, ....... 



147 

149 
149 
180 

367, 370, 374, 421 
78, 92, 276, 306, 329 
92 
92 

442 

219 
372 



Calcifications, combination of, with new-formations of denti 
of the pulp, ...... 

consequent upon inflammation 
senile root-membrane, . 
Cancer, cystoid-gelatinous, of the upper jaw, 
epithelial, of the gums, 
jaws, 
fibrous, of the gums, .... 

jaws, .... 

gelatinous, of the jaws, 
medullary, of the gums, . 
jaws, . 
melanotic, of the dental sac, 

intermaxillary bone, 
of the root-membrane, 
Canine teeth, description of the, . 
Cantharides, effects of, upon the root-membrane, 
Carcinoma, see Cancer. 

Caries of the teeth, 

acute or moist, . 
appearances presented by the cement in, 
dentine in, 
enamel in, 



irritations 



357. 



. 296 
191, 233 

. 191 

. 25 

. 351 

. 320 

. 349 

. 351 

. 351 

. 351 

. 321 

. 350 

. 350 

. 350 

. 317 

. 34 

. 215 



387 et passim 
. 391 
. 384 
. 376 



448 



ALPHABETICAL INDEX. 



Caries, artificial, 

carbonacea, ....... 

cartilaginous softening of dentine in, . 

change in the color of the hair consequent upon 

chronic, ....... 

of the dentine, .... 

consolidation of the dentinal fibrils in, 
deposits of pigment in the enamel in, . 
diminished consistence of the enamel in, . 
translucency of the dentine in, . 
discoloration of the dentine in, . 
extension of, to the root, .... 

frequency of, see Frequency of Caries, 
historical sketch of, .... . 

increased translucency of the surrounding dentine in 
increased transparency of the enamel in, . 
interna, .... 191, 309, 371. 372, ! 

localities of, 

neuralgic affections consequent upon, 

of artificial teeth, ......: 

pivoted teeth, ....... 

reinserted human teeth, ..... 

teeth made from hippopotamus-ivory, . 
signification of, . . . 
distinguished from that of bone, . . i 
the different kinds of teeth, .... 

permanent teeth, 

milk teeth, 

roots of permanent teeth, .... 
teeth of animals, ..... 
wall of the antrum, the cause of facial neural 

sicca, 

symmetrical affection of corresponding teeth with, 

theories of, 

undermining, of the dentine, .... 
enamel, .... 

white, 

Carious teeth, amaurosis consequent upon, 
deafness consequent upon, 
effects of, upon the rest of the body, 
neuralgic affections of the ear consequent upon, 
ptosis consequent upon, .... 
Cartilaginous softening of carious dentine, . 
Cases illustrating neuroses depending upon affections of the 
Castor oil, effects of, uron the root-membrane, 
Catarrhal inflammation of the antrum, .... 

gums, .... 



PAGE 

374, 375, 407 
. 416, 425 

387 et passim 



387 et passim 
389 et passim 
323, 386, 413 
378 
379 
384 
384 
392 
397 
368 



4, 413, 421, 422 

. 393 

438 et p 

4, 370, 406, 414 

. 406 

404, 400, 414 

. 400 

. 

37, 370. 374, 421 

. 393 

. 304 

. 396 

. 390 

. 410 

iftS, . . 442 

390, 423, 425 

. 309 

. 411 

. 389 

. 382 

. 408 

. 439. 441 

. 441 

403 et \ 

. 441 

. 437. 440 

^~ 

teeth, . 435 

. 215 

229 

. 192 



ALPHABETICAL INDEX. 



449 



Cavity of the mouth, bony framework of the, 
Cement, ........ 



caries of the, ......... 391, 

changes in the, in connection with the process of shedding the 

teeth, 77 

development of the, 69 

hypertrophy of the, . . . . 271 

in grooved teeth, ......... 149 

interstitial hypertrophy of the, 276 

resorption of hypertrophic, 274 

junction of the, with the dentine, 53 

neuralgias consequent upon hypertrophy of the, . . . 272 

new-formations of, ....... . 272, 312 

perforating resorption of the, 274 

peripheral-concentric hypertrophy of the, .... 276 

resorption of hypertrophic, ..... 273 

progressive proliferation of the, 437 

resorption of senile, 247 

senile thickening of the, ........ 244 

Cervical plexus of nerves, affections of the, consequent upon irritations 

of the dental nerves, 442 

Changes in the jaws during the second dentition, 91 

form of teeth, indicative of syphilis, .... 146 

temporary and permanent dental arches compared, . 95 

Chondromata of the jaws, . . . ' . . . . . . 339 

Cicatrization of the socket, ......... 258 

variation in the position of adjacent teeth dieting. . . 263 

Ciliary nerves, affections of the, consequent upon abscesses of the root, 438 
affections of the, consequent upon exfoliations of the 

alveolar process, 438 

affections of the, consequent upon irritation of the tri- 
facial nerve, 438 

affections of the, consequent upon the impaction of 

foreign bodies in the teeth and jaws, .... 438 

Classification of malformations of the teeth, 157 

the teeth, 30 

Cleavage of the teeth, 29, 376 

Cleft-palate, 89 

Coalition of the roots, 147, 152 

Coating upon the teeth, . ' 357 

living organisms in the, ..... 357 

Colloid deposits in the pulp, 237 

Concrescence of roots, 147, 152 

facial neuralgia consequent upon the, . . . 435 

Condyle of the lower jaw, senile wasting of the, ..... 270 

Condyloid or nodular enlargements upon the extremities of roots, 138, 139 

Conical teeth, 100, 102 

29 



PAGE 
21 

51 
421 



450 



ALPHABETICAL INDEX. 



of th 



Consecutive atrophy, 

Consolidation of the dentinal fibrils in caries, 
Convulsions during the first dentition, . 

in connection with anomalies in the 
Copper, effects of, upon the root-membrane, . 
Coronoid process of the lower jaw, senile wasting 
Cracks in the enamel, ..... 
Cretefactions in the pulp, .... 
Croton oil, effects of, upon the root-membrane, 
Croupous inflammation of the gums, 
Crowns, axial torsions of the, 

flexions of the, ..... 

surfaces produced by friction upon the, 

and roots, dwarfish, .... 

Cuticle of the enamel, ..... 

Cystoid-gelatinous cancer of the upper jaw, . 

Cysto-myxoma of the jaws, .... 

Cysto-sarcoma adenoides, .... 

of the jaws. .... 

Cysts, dentigerous, 

of the antrum, 

jaws, 

ovarian, containing rudimentary teeth, 
Cytoblastions in the root-membrane, 



Deafness consequent upon caries, . 
Deciduous teeth, see Temporary Teeth. 
Defective formation of the crowns and roots, 
Defectively developed enamel, histology of, 
Defects in the enamel, causes of, . 

wedge-shaped, upon the facial surface of the neck, 
Deficiency of milk teeth, 

permanent teeth 
Degeneration of the parenchyma of the embryonic pulp 
pulp into a soft, greasy mass, 

Density of the teeth, 

Dental arches, comparison of the changes in the temp 
manent, . 
canal in old age, 



d dentition, 



30, 



cap, . 
cartilage, 



posterior, 

membrane, inflammation of the external, 
pulp, see Pulp. 

ridge, 

sac, development of the, . 



14 



orarv and 



PAGE 

. 232 
386, 413 
. 434 
. 435 
. 215 
. 270 
168, 376 
. 234 
. 215 
. 196 
. 132 
. 130 
. 247 
. 157 
51, 69 
. 351 
. 349 
. 344 
. 343 
. 172 
. 351 
. 331 
. 172 
59, 317 

. 441 



2 and 



per- 



43 



244. 



139 
143 
Note 
253 
107 
104 
170 
241 
28 

95 
242 

69 
420 

61 

205 

61 
64 



ALPHABETICAL INDEX 



451 



Dental sac, melanotic cancer of the, 
primary stage of the, . 
sarcomatous proliferation of the 
Denticolae, ..... 
Dentinal canals or tubes, 

cells, .... 

inversion of the layer of, 

fibres, .... 

consolidation of the, in caries, 

germ, development of the, 
primary stage of the, 

globules, .... 

sheaths, of E. Neumann, 
Dentigerous cysts, .... 
Dentine, 

abscesses in the, 

adhesion of the pulp to the, 

appearances presented by carious, 

cartilaginous softening of the carious 

chronic caries of the, 

combination of calcifications with new-formations 

concentrically laminated new-formations of, 

diminished translucency of carious, 

direction of the development of the, 

discoloration of carious, .... 

duration of the development of the, 

growth of the radical portion of the, 

hardness of the, ..... 

increased translucency of the contiguous port 

in grooved teeth, 

interglobular spaces of the, 

interstitial development of, 

intertubular tissue of, 

junction of the cement with the, 
enamel with the, 
pulp with the, 

new-formations of, . 

of repair, .... 

of animals' teeth, abscesses in the, 



of the tusks of elephants, new-formation of osseous substance 

with abscesses in the, 188, 304 

red color of the, with inflammation of the pulp, . . 183, 370 

secondary, 289 

senile, 242 

sensitiveness of the, 56 

theories concerning the mode of development of the, . 
undermining caries of the, ...... 



357 



PAGE 

350 

62 

346 

, 358 

43 

54 

295 

44 

373, 386, 413 
65 
61 
45 
44 
172 
43 
187 
241 
384 
387 et passim 
389 et passim 
296 
289 
384 
66 
384 



.70 

. 29 

of carious, 386 

. 145 

. 45 

. 294 

. 45 

. 53 

. 50 

. 54 
286 et passim 

. 289 

. 187 



of, 



452 



ALPHABETICAL INDEX. 



Dentition, see First, Second, and Third Dentition. 
Development of the cement, ..... 

dentine, 

enamel, ..... 

germs of the first and second 
molars, . 
interstitial, of hone, 

dentine, . 
of malformations, mode of the, 
the teeth, .... 

wisdom teeth, 
Digitalis, effects of, upon the root-membrane, 
Dilaceration, ....... 

Diminution in the size of the pulp-cavity and dental canal 
Diphtheritic inflammation of the gums, 
Diphtheritis, ........ 

Displacement, retention of teeth without, 
Distinctions between the milk and permanent teeth, 
Double or twin-malformations, .... 

Dropsy of the antrum, ...... 

Durability of the enamel, ..... 

Dwarfish malformations of the crowns and roots. 
Dyscrasic periostitis of the jaws. .... 

Ear, neuralgic affections of the, consequent upon carie 
Edentulous jaws, ...... 

Effects of carious teeth upon the rest of the bodv 

various substances upon the, 
Elasticity of the teeth, . 
Elephants' teeth, musket-balls in, . 
Empyema of the antrum. 
Enamel, 

appearances presented by carious, . 

cap. appearances presented by the carious, 
detachment of the, .... 

causes of defects in the, .... 

cells, ....... 

cracks or fissures in the, .... 

deposits of pigment in carious, 

direction of the development of the. 

durability of the, ..... 

fibres, ....... 

germ, ....... 

germs of permanent teeth with a single root 
the first and second permanent mol 
wisdom teeth, 

hardness of the, ..... 



permanent 



92, 276, 306 



in old age 



14 






441 

220 

403 

215 

30 

301 

229 

4-3 

370 

379 

47 

2 and Xote 
47, 03 
B, 370 

ra 

66 



ALPHABETICAL INDEX. 



453 



Enamel, histological appearances of defectively developed, 

irregular distribution of the, . 

junction of the, with the dentine, . 

membrane (Nasmyth's), . 

appearance of the carious 
in old age, 

new-formations of, . 

nodules, ■ 

of grooved teeth, .... 

organ, ...... 

prisms, 

property of double refraction of the, 

senile, 

striae of the, ..... 

theories concerning the mode of developmen 

thickness of the, .... 

undermining caries of the, 
Enchondroinata of the jaws, . 
Enostoses of the alveolar process, . 

jaws, 

Entozoa in the antrum, .... 

Epilepsy consequent upon exostosis of the roots 
Epileptiform paroxysms in association with anomalies 

dentition, .... 
Epileptiform paroxysms during the first dentition 
Epithelial cancer of the gums, 
jaws, 
Epulis, ...... 



flbromatosa, 
sarcomatosa, 

varieties of, . 
Erosion (Note), .... 
Eruption of the milk teeth, . 

intervals between the, 
first permanent molars, 
permanent teeth, . 
second permanent molars, . 
wisdom teeth, 
Exanthemata, inflammation of the gums in the, 
Exanthematous periostitis of the jaws, . 
Excentric atrophy of Kokitansky, . 
Exostoses of the cement, .... 

cement, prosopalgia consequent upon, 
alveolar process, . 

interstitial developm 
roots, epilepsy consequent upon, 
Experiments with different substances upon the teeth, 



of the 



in the second 



ent of 



PAGE 

143 

141 

50 

51, 69, 165 

381 

247 

296 

134 

144 

62 

47 

50 

246 

48 

64 

47 

382 

339 

331 

337 

353 

436 



322 



272, 



228, 
bone in, 



454 



ALPHABETICAL INDEX. 



in connection with 



the opera- 



30, 168, 



Extension of caries to the roots, ........ 

Extraction of teeth, a special cause of facial neuralgias, 

Facial neuralgia consequent upon caries of the wall of the antrum, . 

imbedded teeth, 
exostoses, . 
the concrescence of roots 

Fatty degeneration of the pulp, 

resulting from inflammation 
of milk teeth, 
Eibro-chondroma of the jaws, 
Fibromata of the gums, . 
jaws, . 
Fibrous cancer of the gums, . 
jaws, . 
Filling, importance of new-formations 

tion of, .... 
First dentition, .... 

convulsions during the, 
diseases occasioned by the, 
epileptiform paroxysms during the 
reflex symptoms during the, . 
Fissures or cracks in the enamel, .... 
Fistula, buccal, ....... 

in the gum, 

of the antrum, ...... 

salivary, 

Flexions and torsions of the crowns and roots, 

of the roots, ...... 

Foreign bodies in the antrum, .... 

teeth, the cause of affections of the ciliary nerves, 
Formation, defective, of the crowns and roots, 
of the teeth, irregularities in the, 

Fractured teeth, 

cases of, 

conditions necessary for the union of. 
union of, longitudinally, 
Fracture of the alveolus, ..... 

Fragilitas vitrea, ....... 

Frequency of caries, ...... 

influence of age upon the, . 

diseases of the general sy 

the, 
family upon the, 
food upon the, . 
locality upon the. 
occupations upon the, 



stem 



210. 
219, 



223. 



upon 



400. 



PAGE 

392 
432 

442 
435 
315 
435 
232 
191 
233 
339 
319 
340 
351 
351 

300 
73 
434 
199 
435 
434 
376 
219 
198 
352 
221 
130 
132 
230 
438 
139 
98 
307 
307 
309 
311 
253 

397 
399 

413 
400 
402 
400 
402 



ALPHABETICAL INDEX. 



455 



Frequency of caries, influence of popular customs upon the, 

race upon the, 
sex upon the, 

the use of tobacco upon the, 
in the different kinds of teeth, 

Fusion of teeth, see Blending. 



Ganglions and nerves, anatomical changes in the, in neuralgias, 
Gangrene of the mouth (Noma), . 

pulp, moist and dry, . 
Gangrenous degeneration of the root-membrane, 
Gelatinous cancer of the jaws, 
tumors of the jaws, 
Glands, mucous, ...... 

salivary, 

secretion of the salivary, . 
Globular masses of the dentine, 
Globules, dentinal, ..... 

Gold, effects of, upon the root-membrane, 
Groove, dental, ...... 

posterior dental, .... 

Grooved teeth, peculiarities of the tissues in, 

Growth of the jaws, 

direction of the, . 
lower jaw, measurements of the, 

"Gumboil," 

Gums, 

abscesses in the, 

action of lead upon the, 

acute or inflammatory oedema of the, . 

angiomata of the, 

atony of the, 

atrophy, senile, of the 

bloodvessels of the, 

cancer of the, 

epithelial cancer of the, 

epithelium of the, 

fibromata of the, . 

fibrous cancer of the 

fistulae in the, 

glands of the, 

hypertrophy of the, 

inflammations of the, see Inflammation. 

in mercurial salivation, 

lancing the, ...... 

medullary cancer of the, 

nerves of the, 



456 



ALPHABETICAL INDEX, 



Gums, new-formations of the, 
' papillae of the, 
papilloma of the, 
sarcoma of the, . 
scorbutic, 
secretion of the, . 
senile atrophy of the, . 
vascular tumors of the, 



PAGE 

319 
57 
281, 319 
320 
255 
355 
254 
319 



Hair, change in the color of the, resulting from caries 

Hardness, Moh's scale of, 

of the dentine, 

enamel, 

Hard tissues of the teeth, 

Harelip, 

Hearing affected by diseased teeth, 
Herpetic (?) inflammation of the gums, 
History of caries, ...... 

Horny character of senile dentine, 
Hydrargyriasis, ..... 

Hydrocephalus, teeth in a case of congenital 

Hydrops antri, 

Hypertrophies, ..... 
Hypertrophic cement, interstitial resorption of, 
perforating resorption of, 
peripheral resorption of, 
root-membrane, pigment deposits in the 
Hypertrophy of the alveolar process, . 

cement, .... 

neuralgias caused by, 
interstitial, 
peripheral concentric 
gums, .... 
root-membrane, 

Incisors, description of the, .... 

Inflammations, 

Inflammation of the gums, .... 

during the first dentition. 

during the second dentition 

catarrhal, . 

causes of, 

croupous, 

diphtheritic, 

herpetic (?), 

in syphilis, . 

in the exanthemata 



!29, 231 



438 

29 

29 

29 

43 

89 

441 

195 

368 

242 

205 

148 

331 

271 

274 

274 

273 

279 

228 

271 

272 

277 

32 
176 
192 
200 
204 
192 
193 
196 
205 
195 
195 
195 



ALPHABETICAL INDEX. 457 

PAGE 

Inflammation of the gums, modified by individual peculiarities, . . 194 
phlegmonous, ...... 198 

rare sequels of, •. 201 

suppurative, 198 

the origin of ulceration, .... 194 
mucous membrane and periosteum of the antrum, 

consequent upon that of the root-rnembrane, . 229 
nasal mucous membrane and periosteum, conse- 
quent upon that of the root-membrane, . . 228 

pulp, . . ■ 176 

acute, 176, 179 

changes in the bloodvessels in, . .180 

nerves in, . . . . 181 

chronic, 176, 179, 186 

circumscribed, ...... 178 

terminating in acute or moist grangrene, . 182 

general, 178 

leading to that of the root-membrane, . . 192 

leads to atrophy, 191 

calcifications, ..... 191 
fatty degenerations, .... 191 

redness in, 178 

suppurative, 177, 179, 186 

the cause of the reddish color of dentine, . 183 

increased volume in, 178 

root-membrane, 204 

changes in the hard tissues of the 

root in, 212 

acute, 205, 206 

chronic, .... 205, 208 
consequent upon that of the pulp, 192 

etiology of, 213 

in animals, 222 

resorption of the alveolus in, . 213 
resulting in gangrene, . . . 211 

stages of, 205 

Inflammatory or acute oedema of the gums, 198 

Injection of the alveolar arteries, 60 

Insanity, resulting from the difficult eruption of a wisdom tooth, . 435 

Interalveolar bloodvessels, . . .59 

nerves, 60 

Interglobular spaces of the dentine, ....... 45 

Intermaxillary bone, melanotic cancer of the, ..... 350 

Interstitial development of bone, . . . .78, 92, 276, 306, 329 

dentine, 294 

facets from the friction of contiguous crowns, . . . 252 
growth of bone in the jaws, 92 



458 



ALPHABETICAL INDEX. 



Interstitial hypertrophy of cement, 

resorption of bone in the jaws, 

hypertrophic cement, .... 

Intertubular tissue of the dentine, . ...... 

Intervals between the eruption of the milk teeth, .... 

Inversion of the layer of dentinal cells, ..... 

Iodine, effects of, upon the root-membrane, ..... 

Irregularities in the arrangement of entire sets of teeth, 

distribution of the enamel, .... 

formation of teeth, 

number of permanent teeth, . 
position of the milk teeth, .... 
permanent teeth, . 
separate permanent teeth imbedded within 
the jaw, . . . . 
size of the milk teeth, ..... 
permanent teeth, .... 
structure of the teeth, 



Jaw, see Upper and Lower Jaw, and Max 
Jaws, abscesses in the, . 

atrophy of the, . 

cancer of the, 

changes in the, during the second dentition 
arch of the, 

chondromata of the, . 

cystoid-gelatinous cancer of the upper 

cysto-myxoma of the, . 
sarcoma of the, . 

cysts of the, .... 

direction of the growth of the, 

edentulous, .... 

enchondromata of the, 

enostoses in the, . 

epithelial cancer of the, 

fibro-chondromata of the, . 

fibroma of the, 

fibrous cancer of the, . 

gelatinous cancer of the, 
tumors of the, 

growth of the, 

interstitial growth of bone in the 

medullary cancer of the, 

melanotic cancer of the, 

myeloid sarcoma of the, 

myxomata of the, 

necrosis of the, during dentition, 



ALPHABETICAL INDEX. 



459 



Jaws, osteoid-chondroma of the, . 

osteophytes upon the, . 

osteo-carcinoma of the, 
sarcoma of the, . 

periosteal sarcoma of the, . 

periostitis of the, see Periostitis. 

purulent infiltration of the, . 

relative growth of the, 

sarcomata of the, 

senile wasting of the, . . . 

wolf's, ..... 
Juga alveolaria, .... 



Lancing the gums, 
Leptothrix buccalis, 

reaction of, with iodine and acids, 
Longitudinal fracture through the crown and root, union of a, 
Lower jaw, see Jaw. 

articulation of the, 

description of the, . . ... 

direction of the growth of the, .... 

measurements, showing the relative growth of the, 

movements of the, ...... 

ossification of the, ...... 

periostitis of the, see Periostitis. 

senile changes in the, ...... 



PAGE 

339 

335 
351 
347 
347 

225 

92 

343 

257 

89 

23 



. 199 
7 et passim 
. 358 
. 311 



26 
24 

89 
92 
26 
89 

269 

154 
157 
157 



Malformations of the teeth, ....... 

classification of the, 

dwarfish, of the crowns and roots, . 
general, of the crown of a molar, with undeveloped 
roots, in connection with the deeply imbedded crown 

of a wisdom tooth, 

mode of the development of the, ..... 
monstrous, of the coronal with a well-formed radical 

portion, 

of the teeth of animals, 

Malposition of the teeth, amaurosis consequent upon, .... 

neuralgias consequent upon, . . . 435, 
Masseter muscles, senile wasting of the, ...... 

Mastication, actions of the muscles in, 27, 270 

movements in, . . . . . . . . 27, 270 

muscles of, . . . . . . . . . .27 

Maxillae, see Jaws. 

Maxillary periosteum, abscesses in the, 222 

atrophy of the, 257 



158 
155 

158 
167 
440 
436 
269 



460 



ALPHABETICAL INDEX. 



51, 69 



first 



and 



econd per 



Maxillary periosteum, inflammatory affections of the, from those of 
the pulp or root-membrane, 
sinus, ....... 

Measurements showing the relative growth of the jaws 
Medullary cancer of the gums, 
jaws, 
Melanotic cancer of the dental sac, 

intermaxillary bone 
Membrane, Nasmyth's enamel, 

of the root, see Root-Memhrane. 
Meningoencephalitis, consequent upon the extraction of a tooth, 
Mental aberration, consequent upon the second dentition, 
foramen, ..... 

Mercurial salivation, gums in, 

Mercury, effects of, upon the root-membrane, 

Micrococcus, ....... 

Milk teeth, see Temporary Teeth. 

Mixed saliva, see Saliva, .... 

Moh's scale of hardness, .... 

Molars, description of the, 

development of the enamel germs of the 
manent, ...... 

eruption of the first permanent, 

second permanent, . 
Monstrous malformation of the crown with well-formed roots, 

outgrowth of dentine and cement upon 
Mouth, bon}' framework of the cavity of the, 
gangrene of the (Noma), . 

the flat, 

grinning (Fletschenmund), 
negro (os ^Ethiopum), 
senile (os senile), 
Movements of the lower jaw. 
Mucin, ....... 

Mucor, ....... 

Mucous glands, 

membrane of the antrum, inflammation of 

upon that of the root-membrane, . 
membrane of the antrum, polypi of the, . 

mouth, new-formations of the 
nasal cavity, inflammation of the, consequent 
upon that of the root-membrane, 
secretion of the, . ..... 

Mucus, 

Multilocular ovarian cysts containing imperfectly developed teeth 

Musket-balls in the teeth of elephants, 

Myeloid sarcomata of the jaws, 



the root, 



the, 



199 



consequent 



222 
24 
93 
321 
350 
350 
350 
165 

223 
435 
24 
195 
215 
357 

355 
29 
35 



86 
76 

158 
169 
21 
201 
108 
109 
108 
110 

354 
194, 415 

354 



229 

321 

22S 
355 
354 
172 
301 
347 



ALPHABETICAL INDEX. 



461 



Myeloplaxes, 59, 317 

Myxoinata of the jaws, 348 



the alveolar process, 
gums, 

hard dental tissues, 
oral mucous membrane, 
pulp, .... 



228 
165 
226 

212 
223 
426 
181 
430 
238 
436 
426 
430 



Nasal cavity, inflammation of the mucous membrane and. periosteum 
of the, consequent upon that of the root-membrane, 

Nasmyth's membrane, 51, 69, 

Necrosis of the alveolar process, 222, 

cement, consequent upon inflammation of the root- 
membrane, ....... 

jaw, during dentition, ..... 

Nerves and ganglions in neuralgias, anatomical changes in the 
of the pulp in inflammation, changes in the, 
resection of, for the relief of neuroses, 

Net-like atrophy of the pulp, 

Neuralgia in a molar, resulting in death, .... 
Neuralgias, anatomical changes in the nerves and ganglions in, 

clinical phenomena of, 

consequent upon caries, ..... 438 et passim 
Dobbelin's operation for the relief of, .... 434 

exciting causes of, 427 

extraction of teeth, a special cause of, .... 432 

foci of irritation in, 427 

irradiation of the pain in, 429 

occasioned by anomalies in the second dentition, . . 435 

impacted teeth, 435 

painful points in, 431 

reflex phenomena in, 431 

resection of nerves in, 430 

Neuritic process [Neuritis], 427, 429 

Neuroses, see Neuralgias, 426 

consequent upon affections of the teeth, abstract of cases of, 

New-formations, 

importance of, in connection with the operation of fill- 
ing, 

in the teeth of animals, .... 

literature of, ...... 

of cement, ....... 

dentine, 

combination of, with calcifications, 
concentrically laminated, . 

enamel, 

osseous substance with abscess in elephants 



435 
284 

300 
297 
286 
312 
286 
296 
289 
296 



ivory, 
188 



. 304 
. 289 
. 319 
. 286 
. 321 
191, 285 



462 



ALPHABETICAL INDEX. 



PAGE 

New-formations of the root-membrane, 316 

osteo-dentinal, 293 et passim 

physiological or pathological signification of, . . 299 
progressive, ......... 434 

dentinal, , . .300 

Nitrous acid salt in the saliva, ........ 355 

Nodules of enamel, 134 

Nodular or condyloid enlargements at the extremities of roots, . 138, 139 
Noma, 199, 201 



Oblique fractures of the crown, exposure of the pulp in, 

roots, 
Odontalgia nervosa ex carie, . 

Odontoblasts, 

Odontolithus, ...... 

Odontomata (Note), .... 

GEdema of the gums, acute or inflammatory 
Oidium albicans, ..... 

Opium, effects of, upon the root-membrane, 
Organ adamantina?, \. 

Os JEthiopum, 

senile, ...... 

Ossification of the lower jaw, 
upper jaw, 

senile root-membrane, 
Osteoid chondromata of the jaws, . 
Osteo-carcinoma of the jaws. 

dentine, 

in the teeth of animals, . 
odontomata, ..... 
sarcomata of the jaws, . 
Osteomata of the cement, 

prosopalgia consequent u 
alveolar process, . 

interstitial 
Osteophytes upon the jaws, . 
Osteopsathyrosis of Lobstein, 

Ostitis, 

Ovarian cysts, teeth in, .... 



Papilla of the gums, .... 

Papilloma of the gums, .... 

Parulis, ....... 

Penicillium glaucum, .... 

Perforating caries, ..... 

resorption of hypertrophic cement. 
Pericellular resorption of the angle of the lower jaw 



pon. 
development 



40. 



of 



311 

309 
177 
54 
361 
155 
198 

195, 358, 406 
215 
163 
108 
110 
89 
88 
255 
339 
351 

293 et jyassiui 
. 297 
169, 316 
169, 343 
. 312 
. 315 
- 327 
in,. 329 
, 22S, 335 

. 367 

. 172 



bon< 

20 



281, 319 
. 196 

357 
et p - 



ALPHABETICAL INDEX. 



463 



changes in 



Periodontitis, 

Periosteal sarcoma of the jaws, 

Periosteum of the root, see Koot-Membrane. 
Periostitis of the alveolar process, consequent upon caries, 
jaw, during the first dentition, . 
second dentition, 
dyserasic, 
exanthematous, 
rheumatic, . 
specific, . . 
traumatic, . 
lower jaw, symptoms of, 
upper jaw, symptoms of, 
Peripheral-concentric hypertrophy of the cement, 
resorption of hypertrophic cement, 

the angle of the lower jaw, 
Permanent and temporary dental arches, comparison of the 
the, .... 

teeth, arrangement of the, . 
caries of the different, 
carious roots of the, 
deficiency of the, 
description of the, 
eruption of the, . 
imbedded within the jaw, irregular position of, 
irregularities in the arrangement of entire sets of, 
irregularities in the number of, 

position of separate 
size of, 
Phlegmonous inflammation of the gums, 
Phosphornecrosis, . 

Phosphorus, effects of the fumes of, upon the teeth and 
tures, ........ 

Pigment deposits in atrophic pulps, 
carious enamel, 
the hypertrophic root-membrane, 

Pivoted teeth, caries of, 

Polypi of the mucous membrane of the antrum, . 

pulp, 

root-membrane, .... 

Posterior dental groove, 

Primary atrophy, 

Progressive dentinal new-formation, 

new-formations, 

proliferation of cement, 
Proliferation, sarcomatous, in the pulp, 

of the dental sac, 



205, 
adjacent struc- 



PAGE 

205 
347 

222 
223 
202 
224 
224 
224 
224 
224 
224 
225 
276 
273 
269 

95 

40 

394 

396 

104 

32 

82 

122 

108 

99 

112 

98 

198 

214 

214 
241 
378 
279 
406 
352 
285 
318 
85 
232 
300 
434 
437 
191 
316 



464 



ALPHABETICAL INDEX. 



Prosopalgia, see Facial Neuralgia. 

Protococeus dentalis, 

Pterygoid muscles, senile wasting of the, .... 

Ptosis consequent upon dental caries, 

Ptyaline, 

Puccinia graminis, ......... 

Pulp, dental, 

abscesses in the, . . . . . . . 1 

adhesion of the, to the dentine, ..... 

atrophy of the, 

resulting from inflammation, 

basis tissue of the, 

bloodvessels of the, ....... 

calcifications of the, ....... 

resulting from inflammation. " . 

colloid deposits in the, ...... 

combination of different atrophic processes in the, 

cretefaction of the, 

degeneration of the, into a soft, greasy mass, 

parenchyma of the embryonic, . 

fatty degeneration of the, ...... 

resulting from inflammation, 

gangrene, moist and dry, of the, .... 

inflammation of the, see Inflammations. 

in transverse and oblique fractures, exposure of the, . 

junction of tbe, with tbe dentine, 

nerves of the, .... 

net-like atrophy of the, 

new-formations of the, 

of the milk teeth, fatty degeneration of the 

pigment deposits in atrophic, 

polypus of the, . 

sarcoma of the, . 

sarcomatous proliferation of the, 

sclerosis of the, .... 

cavity and dental canal, diminution in the 
Purulent infiltration of the alveolar process. 

jaws, . 
Pyorrhoea alveolaris, ..... 

Eedness of the pulp in inflammation, ..... 
Reddish color of the dentine with inflammation of the pulp, 

teeth, occurs as an anomaly of formation, 
Reflex phenomena in connection with neuralgias, 

the first dentition, .... 

the second dentition 



size of, in old i 



372, 



437, 
354, 



ige, 



PAGE 

415 
269 
440 
365 
415 
54 
186 
241 
232 
191 
55 
55 
233 
191 
237 
240 
234 
241 
171 
232 
191 
182 



311 
54 
56 

238 

233 
241 

286 
191 
240 
242 
217 
225 
211 



18 



Reinserted human teeth, caries of, 



17S 
3. 370 
186 
431 
434 
435 
404 ; 406. 414 



ALPHABETICAL INDEX. 



465 




the re 



plantation 



Replantation of teeth, ..... 
Eesection of nerves for the relief of neuroses, 
Resorption of bone in the jaws, interstitial, . 

hypertrophic cement, interstitial, 
perforating, 
peripheral, 
senile dentine and cement, 
the angle of the lower jaw, peripheral and pericellular, 

the alveolar process, senile, 

the alveoli, after extraction of the teeth, 

consequent upon inflammation of the root- 
membrane, ...... 

previous to the eruption of the teeth, partial, 
the hard tissues of the root, consequent upon inflamma- 
tion of the root-membrane, 
process in shedding the teeth, 
Retention of teeth without displacement, 
Rheumatic affection of the root-membrane, 
periostitis of the jaws, 

Ridge, the dental, 

Root-membrane, 

abscesses of the, . 

affections of the, consequent upon 

and transplantation of teeth, . 
affections of the, consequent upon the 

substances, 
atrophy of the, . 
bloodvessels of the, 
calcification of the, . 
cancer of the, 
cytoblastions in the, . 
gangrene of the, . 
hypertrophy of the, 
inflammation of the, see Inflammation 
myeloplaxes in the, 
nerves of the, 
new-formations of the, 

symptoms of the 
ossification of the, 

pigment deposits in the hypertrophic, 
polypi of the, .... 
rheumatic affection of the, . 

senile, 

tumors of the, .... 
Root, periosteum of the, see Root-Membrane. 
Roots, abscesses of the, causing affections of the ciliary nerves 

30 



PAGE 
216 

430 
92 
274 
274 
273 
245 
269 
266 
259 

213 
71 

212 

77 

127 

216 

224 

61 

58 

210 

215 



of various 

. 214, 215 
. 255 
. 59 
. 255 
. 317 
59, 317 
. 211 
. 277 



59, 



317 

60 

316 

317 
256 
279 
318 
216 
255 
316 



438 



466 



ALPHABETICAL INDEX. 



Boots and crowns, dwarfish, 157 



flexions and torsions of the, 



130 



condyloid or nodular enlargements at the extremities of the, 138, 139 

diminished number of, 140 

extension of caries to the, 392 



facial neuralgia, consequent upon the concrescence of, 

flexions of the, .......... 

formation of the, when completed, 

general monstrous malformation of the crown with well-formed, 
general malformation of the crown of a molar with undeveloped, 

growth of the, 

of permanent teeth, caries of the, 
supernumerary, ....... 

union of the, ....... 

unusually long or thick, divergent and curved, . " 



Saliva, acidity of the, . 
alkalinity of the, 
appearance and pro] 
the mixed, .... 

nitrous acid salt in. 
sugar in, . 
sulphocyanic acid in, 
urea in. 
Salivary calculus, .... 
fistula, .... 
glands, .... 
secretion of the, . 
Sarcomata of the gums, 
jaws, . 
pulp, . 
Sarcomatous proliferations in the pulp, 

of the dental sac 
Sclerosis of the pulp, .... 

Scorbutic gums, 

Scrofulous teeth (Note), . 

Second dentition, ..... 

changes in the jaws during the. 
convulsions caused by anomalies in the. 
diseases caused by the, 
epilepsy caused by anomalies in the. . 
mental aberration caused by anomalies in 
neuralgias caused by anomalies in the. 

Secondary atrophy, 

dentine, 

osteoids, 



140, 14 



the, 



219, 



435 
132 

70 
158 
158 

70 
396 
136 
162 
138 



355 
356 
354 
355 
355 
356 

365 

354 
320 

191 
240 

142 
91 

201 



ALPHABETICAL INDEX, 



467 



Secretion of the gums, . 

mucous glands, . 

membrane, 
salivary glands, . 
Senile alveolus, . . . 

, atrophy, .... 
of the gums, . 
cement, .... 

calcification of the root-membrane, 
changes in the angle of the lower jaw 

dentine, 

enamel, 

membrane, 
flattening of the articular eminence of the 
ossification of the root-membrane, 
resorption of the alveolar process, 
cement, 
dentine, . 
root-membrane, .... 
wasting of the coronoid processes and condy 
masseter and pterygoid muse 
maxillae, . . . 
Sensations produced in the teeth by certain sound 
Sensitiveness of the dentine, . 
Shedding the teeth, process of, . 

Socket, atrophy of the, 

cicatrization of the, . . 
Specific gravity of the teeth, 

periostitis of the jaws, 
Spirillum, ....... 

Stomatitis, ....... 

hemorrhagica, .... 

ulcero-membranacea, . 
Structure of the teeth, irregularities in the, . 

Supernumerary roots, 

teeth, 

Surfaces upon the crown, produced by friction, 

Sutura incisiva, 

Syphilis, changes in the form of teeth indicative 
inflammation of the gums in, . 



temp 



Tartar, 



anesthesia of the, 
artificial caries of the, 
blending or fusion of adjacent, 



les u 
es, 



f the 



of, 



bone 



lower jaw, 



100, 



. 443 
374, 375, 407 
. 147 



468 



ALPHABETICAL INDEX. 



PAGE 

Teeth, caries of artificial, 374, 376, 406, 414 

reinserted human teeth, .... 404, 406, 414 

the, 357 

different kinds of, 393 

changes in the form of, indicative of syphilis, .... 146 

classification of the, 30 

cleavage of the, 29, 376 

coalescence or concrescence of adjacent, 147 

coating upon the, ......... 357 

formation of the. ...... 361 

living organisms in the, .... 357 

conical, 100, 102 

deficiency of, 104, 107 

density of, 28 

development of the, . . . . . ... . .60 

distinctions between temporary and permanent, ... 40 
effects upon the hearing- caused by diseased, .... 441 

elasticity of the, 30 

extraction of, a special cause of neuralgias, .... 432 

fractured, 307 

cases of, 307 

conditions necessary for the union of, 309 

general characters of the, ........ 28 

hard tissues of the, ......... 43 

in a case of congenital hydrocephalus, 148 

in ovarian cysts, . . . . . . . . .172 

irregularities in the, see Irregularities. 

Magitot's experiments with various substances upon the, . . 407 

malformations of the, see Malformations. 

neuralgias consequent upon impacted. ..... 435 

neuroses consequent upon affections of the. abstract of cases of. 435 

new-formations of the, sec New-formations. 

of animals, caries of the, ........ 410 

malformations of the, . . . . . .167 

new-formations of the, ...... 297 

wear of the, 253 

of elephants, musket-balls in the, 301 

peculiarities of the tissues in grooved, ..... 44 
relation between affections of the uterus and those of the (Xote), 4^.2 

pivoted, caries of, 406 

reinserted human, caries of, ... 374. 376, 400, 414 

replantation of, ......... 216 

retention of, without displacement, ...... 127 

shedding the, ... ■ 77 

resorption in connection with, . . . "" 

specific gravity of, 2S 



ALPHABETICAL INDEX. 



469 



and. 



Teeth, supernumerary, ........ 

transplantation of, . 

trephining the, Dobbelin's operation for the relief 
neuralgia, ........ 

Teething, see Dentition. 

inflammation of the gums attending, . 
rare sequelae of inflammation of the gums attendin 
Temporary and permanent dental arches, comparison of the 

in the, 

Temporary teeth, arrangement of the 
blending of the, 
caries of the, 
deficiency of the, 
description of the, 
distinction between permanent 
eruption of the, 
excessive number of the, .' 
fatty degeneration of the pulps of, . 
intervals between the eruption of the, 
irregularities in the position of the, . 
size of the, 
Tetanus following the extraction of a tooth, 

Theories of caries, 

Third dentition, ......... 

Thrush, ■ . 

Tomes' processes of the dentinal cells, .... 
Torsions and flexions of the crowns and roots, 

axial, of the crowns, ..... 
Transplantation of the teeth, ..... 

Transverse fractures of the crowns, exposure of the pulp in 

root, 

Traumatic periostitis of the jaws, . .... 

Trephining the teeth for the relief of neuralgias, 

Trifacial nerve, affections of the ciliary nerves and apparatus 

from irritation of the, .... 
Trismus cured by the extraction of a first molar 
Tumors of the root-membrane, 

symptoms of the 
Tusks of elephants, abscess in the, 
Twin-malformations, ..... 

distinguished from blended teeth 



of 



changes 



PAGE 

100, 135 
216 
facial 



of vision 



434 

199 
201 

95 

43 

149 

396 

107 

38 

40 

73 

102 

233 

75 

121 

99 

436 

411 

87 

194 

64, 68 

130 

132 

216 

311 

309 

224 

434 



438 

436 

316 

317 

188, 304 

140, 170 

. 149 



Ulceration of the gums consequent upon catarrhal inflammation, . 194 

Undermining caries of the dentine, 389 

enamel, 382 

Underhung, ............ 110 



470 



ALPHABETICAL INDEX. 



Union of roots, 140, 147, 152 

Upper jaw, see Jaw. 

cystoid-gelatinous cancer of the, 351 

description of the, 22 

ossification of the, 88 

periostitis of the. see Periostitis. 

Uterus, relation between affections of the teeth and those of the (Xote), 432 

Upright teeth, 110 



Vascular tumors of the gums, 

Yaso-dentine, 

Vestibulum oris, ...... 

Volume of the pulp, increased in inflammation. 



. 320 
46, 188 

. 218 
. ITS 



Wearing away of the teeth by attrition, forms in which and means by 

which it is effected (Note), ......... 247 

Wedge-shaped defects upon the facial surface of the dental neck, 

White caries, 408 

Wisdom teeth, development of the, 

duplication of the, 140 

eruption of the, ........ 

Wolf's jaw, 



THE END. 



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